• Home
  • Latest
  • Fortune 500
  • Finance
  • Tech
  • Leadership
  • Lifestyle
  • Rankings
  • Multimedia

Trendingnow

1

The millennial generation is split in 2: an older crowd with boomer-style comfort, a younger set going 'back to the early 1900s'

2

Trump pulls back after Iran crosses his red line as U.S. military breaks two-week streak of airstrikes amid talks for potential Hormuz deal

3

'The demographic dividend of the last 40 years is ending': J.P. Morgan says the world is running out of the two things that kept interest rates down

1

The millennial generation is split in 2: an older crowd with boomer-style comfort, a younger set going 'back to the early 1900s'

2

Trump pulls back after Iran crosses his red line as U.S. military breaks two-week streak of airstrikes amid talks for potential Hormuz deal

3

'The demographic dividend of the last 40 years is ending': J.P. Morgan says the world is running out of the two things that kept interest rates down

Elon Musk Explains When He Thinks it’s Okay To Call Someone an Idiot

By
Kirsten Korosec
Kirsten Korosec
Down Arrow Button Icon
By
Kirsten Korosec
Kirsten Korosec
Down Arrow Button Icon
December 21, 2017, 1:50 PM ET
Add Fortune on Google for similar content.

Tesla and SpaceX CEO Elon Musk wants everyone to know that he would only call someone an “idiot” if people were mistakenly under the impression that this person is smart—oh, and he really does love most trains, subways, and London buses.

Taken out of context, Musk’s Thursday tweetstorm—which touched on all those subjects—might seem strange. But it all goes back to a fracas that erupted earlier this month after Wired published comments made by the CEO at an artificial intelligence conference. Musk said that “public transport is painful. It sucks. Why do you want to get on something with a lot of other people, that doesn’t leave where you want it to leave, doesn’t start where you want it to start, doesn’t end where you want it to end?”

Musk called the Wired report “misleading and misanthropic.” But that didn’t stop critics from lashing out at the billionaire entrepreneur’s description of shared transit as an unpleasant safety risk.

And that’s when things escalated.

Jarrett Walker, a high-profile public transit advocate and consultant, jumped into the debate, describing Musk as an elitist and calling his disdain for public transit as “a luxury (or pathology) that only the rich can afford.”

Musk’s response was short—“You’re an idiot”—and it only poured more fuel on an already fiery debate.

After the initial eruption, all seemed quiet until NYT columnist and economist Paul Krugman retweeted out a story from Fortune with one comment “Elon Musk’s idea of a cogent argument, ‘You’re an idiot.'”

It took a couple of days, but Musk fired back with a string of tweets explaining his reasoning, and declaring his love for some public transit.

Idiots can be very dangerous when they seem smart, but aren’t (having “PhD” in their bio is a dead giveaway), as some policymakers may get fooled. That’s what really bothered me about that human cat meme / transit “expert”.

— Elon Musk (@elonmusk) December 21, 2017

I would only call someone an idiot if people were mistakenly under the impression that the person was smart

— Elon Musk (@elonmusk) December 21, 2017

Later, Musk took things officially too far.

His “PhD” is in literature (really), presumably bad fiction

— Elon Musk (@elonmusk) December 21, 2017

For the record, I actually love trains, most subways and London buses.

— Elon Musk (@elonmusk) December 21, 2017

Still, Musk says public transit doesn’t fully solve the problem “as most major cities have been in traffic hell for decades with no solution in sight.”

However, public transit is obviously not fully solving the problem, as most major cities have been in traffic hell for decades with no solution in sight. Multi-level tunnels can solve this, but we need much better tunneling technology, as it is currently super slow and expensive.

— Elon Musk (@elonmusk) December 21, 2017

The upshot? Tunnels. Multi-level tunnels. Which is what his other business, The Boring Company, just happens to be pursuing.

 

About the Author
By Kirsten Korosec
See full bioRight Arrow Button Icon
Add Fortune on Google for similar content.

Latest in

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025

Most Popular

Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Finance
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam
By Fortune Editors
October 20, 2025
Fortune Secondary Logo
Rankings
  • 100 Best Companies
  • Fortune 500
  • Global 500
  • Fortune 500 Europe
  • Most Powerful Women
  • World's Most Admired Companies
  • See All Rankings
  • Lists Calendar
Sections
  • Finance
  • Fortune Crypto
  • Features
  • Leadership
  • Health
  • Commentary
  • Success
  • Retail
  • Mpw
  • Tech
  • Lifestyle
  • CEO Initiative
  • Asia
  • Politics
  • Conferences
  • Europe
  • Newsletters
  • Personal Finance
  • Environment
  • Magazine
  • Education
Customer Support
  • Frequently Asked Questions
  • Customer Service Portal
  • Privacy Policy
  • Terms Of Use
  • Single Issues For Purchase
  • International Print
Commercial Services
  • Advertising
  • Fortune Brand Studio
  • Fortune Analytics
  • Fortune Conferences
  • Business Development
  • Group Subscriptions
About Us
  • About Us
  • Press Center
  • Work At Fortune
  • Terms And Conditions
  • Site Map
  • About Us
  • Press Center
  • Work At Fortune
  • Terms And Conditions
  • Site Map
  • Facebook icon
  • Twitter icon
  • LinkedIn icon
  • Instagram icon
  • TikTok icon
  • YouTube icon

Latest in

katty
CommentaryLeadership
Katty Kay: confidence is the skill that turns thoughts into action—and companies need to start teaching it
By Katty KayJuly 26, 2026
1 hour ago
‘My childhood home is being taken’: Eminent domain for data centers targets properties across a thousand miles of grid expansion in Georgia
EnergyData centers
‘My childhood home is being taken’: Eminent domain for data centers targets properties across a thousand miles of grid expansion in Georgia
By Joshua HongJuly 26, 2026
1 hour ago
Fans Watch Super Bowl LX In California beneath tv screens with betting ads
EconomySports
Gambling becomes America’s favorite pastime as Americans spend more on sports bets than movies, arts, museums, and music combined
By Catherina GioinoJuly 26, 2026
2 hours ago
The Pete behind Jersey Mike’s was only 17 years old when he borrowed $125,000 to buy the chain—with some help from his high school football coach
SuccessFounders
The Pete behind Jersey Mike’s was only 17 years old when he borrowed $125,000 to buy the chain—with some help from his high school football coach
By Marco Quiroz-GutierrezJuly 26, 2026
3 hours ago
Bridgewater Associates ex-recruitment boss reveals the secret ‘unpopularity’ interview test he used on hundreds of candidates at the hedge fund
SuccessThe Interview Playbook
Bridgewater Associates ex-recruitment boss reveals the secret ‘unpopularity’ interview test he used on hundreds of candidates at the hedge fund
By Orianna Rosa RoyleJuly 26, 2026
3 hours ago
One woman holds a "No data centers" sign while another points toward a white house.
EnvironmentData centers
Data centers were actually making electricity costs cheaper, but the $7 trillion buildout with no guaranteed AI demand is threatening the trend
By Sasha RogelbergJuly 26, 2026
3 hours ago

Most Popular

The millennial generation is split in 2: an older crowd with boomer-style comfort, a younger set going 'back to the early 1900s'
Real Estate
The millennial generation is split in 2: an older crowd with boomer-style comfort, a younger set going 'back to the early 1900s'
By Nick LichtenbergJuly 25, 2026
23 hours ago
Trump pulls back after Iran crosses his red line as U.S. military breaks two-week streak of airstrikes amid talks for potential Hormuz deal
Middle East
Trump pulls back after Iran crosses his red line as U.S. military breaks two-week streak of airstrikes amid talks for potential Hormuz deal
By Jason MaJuly 25, 2026
14 hours ago
'The demographic dividend of the last 40 years is ending': J.P. Morgan says the world is running out of the two things that kept interest rates down
Economy
'The demographic dividend of the last 40 years is ending': J.P. Morgan says the world is running out of the two things that kept interest rates down
By Eleanor PringleJuly 24, 2026
2 days ago
An 11-year-old is cleaning his neighbors' trash cans for $10 each—he now has 100K followers as teens face the worst summer job market since 1948
Success
An 11-year-old is cleaning his neighbors' trash cans for $10 each—he now has 100K followers as teens face the worst summer job market since 1948
By Orianna Rosa RoyleJuly 25, 2026
1 day ago
Jensen Huang made his $172 billion fortune on AI chips. His family's $75 million gift to Vanderbilt argues art decides what technology is for
Big Tech
Jensen Huang made his $172 billion fortune on AI chips. His family's $75 million gift to Vanderbilt argues art decides what technology is for
By Sydney LakeJuly 23, 2026
3 days ago
A Hims cofounder fired his entire marketing team for AI. Now his 24/7 online vet service is growing 20% a month
Success
A Hims cofounder fired his entire marketing team for AI. Now his 24/7 online vet service is growing 20% a month
By Sydney LakeJuly 25, 2026
21 hours ago

© 2026 Fortune Media IP Limited. All Rights Reserved. Use of this site constitutes acceptance of our Terms of Use and Privacy Policy | CA Notice at Collection and Privacy Notice | Do Not Sell/Share My Personal Information
FORTUNE is a trademark of Fortune Media IP Limited, registered in the U.S. and other countries. FORTUNE may receive compensation for some links to products and services on this website. Offers may be subject to change without notice.