On Monday, Weill and his wife, Joan, will be honored at the National Academy Foundation’s 30^th Anniversary Benefit gala in Manhattan. Weill founded NAF in 1982 — the foundation supports career-themed academies in finance, hospitality and tourism, and information technology and engineering in more than 500 U.S. high schools. Weill’s philanthropic reach also touches the arts and healthcare – in 1998, he endowed Cornell University’s medical school, known as the Weill Cornell Medical College. He’s also chairman of Carnegie Hall’s board of trustees. And last March, he and his wife announced a $12 million gift to Sonoma State University to help it complete its concert hall.

Indeed, it’s a markedly new (and probably quieter) chapter for Weill.

Until 2006, the 79-year-old banker and financier helped run what was once the world’s biggest bank. Weill essentially built Citigroup (C) into the financial “supermarket” it was when the credit crisis hit. He has been a target of blame for the crisis, having successfully fought changes to laws that had prevented banks, insurers and brokerage firms from merging. At one point after he had stepped down, around the time Citi struggled with huge losses, Weill wanted to help with the bank’s recovery. His offer went unanswered.

Fortune caught up with Weill at his office on the 46^th floor of the General Motors building in Manhattan last week. The space is breathtaking, with panoramic views of Central Park and Fifth Avenue. Weill surrounds himself with reminders of his days on Wall Street. There are photos of the Weills smiling with political elites including the Bushes. And as big supporters of the arts and music, there are also several photos of the couple with renowned cellist Yo-Yo Ma – they consider him a good friend. But what immediately sticks out is a photo of Sandy Weill’s childhood home in Bensonhurst, Brooklyn. It reminds him of his humble beginnings – something he has carried throughout his career, whether on Wall Street or philanthropy.

Below is an edited transcript of Weill’s interview. He talks about charity, education, the economy and Vikram Pandit’s paycheck.

Why is philanthropy important to you?

Basically I spend all my working time working for non-profit organizations. Anything we do is not really just about money, it’s about using the ability that we had developed in our previous lives to work with component people to achieve goals that will make our society a better place.

You founded the National Academy Foundation 30 years ago this year. What’s most inspiring about it?

When you think about the high school education system in the United States we don’t rank in the top 15 of countries. That’s really terrible for somebody who aspires to be a leader in the future. We’ve got to educate our people for where the opportunities are.

One hundred years ago we were happy when these kids didn’t graduate because they were needed back on the family farms. Big job opportunities were the unskilled labor jobs that were in this country and most of those have gone overseas. And now it’s much more service-oriented and high tech.

NAF is done within the public school system. It’s not like a charter school where you’re not dealing with the unions or the local governments. It’s done in partnership with the public school system and companies in the area that are willing to support the program and mentor young people and give these kids in their junior year a summer internship for six weeks which is not just licking envelopes. Most of them do very well and a lot of them get asked to come back during holidays.

What kind of a student were you growing up?

I was a bad student when I went through junior high school and the beginning of high school. My parents moved back to New York right after WWII and they couldn’t find a place to live so they moved in with my grandparents. I was doing lousy so they sent me to military school. Discipline was very good for me. I went for a year and stayed the whole four years and did well there. I thought I was smart enough to become an engineer, so I went to Cornell University for engineering and flunked out by Thanksgiving of my freshman year. I switched into liberal arts. But the discipline I learned really came the four years I was in military school.

Let’s talk about the U.S. economy. What kind of shape do you think it’s in today, compared with where it was at during the financial crisis?

I think that our economy is doing better. I think the earnings season that we’re just about finishing shows American companies performed better than most people thought they ever would. They are very liquid, but they’re not really spending and investing like they could or should because there’s a lot of uncertainty about the future. Executives are wondering where tax rates might fall; what’s going to be the position of our government; is this going to be a friendly environment for businesses; are we going to continue to developing the best and the brightest; are we going to have more open immigration policies that can attract more people around the world?

What do you think is holding up the U.S. from faster economic growth?

I think it would be the uncertainty about the direction of government and policy. I think Europe is also a problem. I think Asia is going to be fine. I think China is going to be fine, but it depends how big a problem Europe’s debt crisis gets.

The U.S. is now going through close to five years of de-leveraging from consumers getting way too leveraged.

How do you think America’s biggest banks have recovered from the financial crisis?

I think the banks are in very good shape right now. I don’t like the new financial regulations. What bothers me the most is I think that banks could be controlled or managed by having good regulations and by having more transparency. I think this whole concept of fixing ‘too big to fail’ is a problem because when you create an environment where you can’t make a mistake then you’re also creating an environment where nothing good is going to happen.

But a lot of Americans blame lax regulations and the big banks for the financial crisis. What would you say to them?

I would say there is enough blame to go around. I think that the financial industry made some mistakes that created issues, our government made mistakes that created issues, the regulators made mistakes that created issues. People made mistakes that created issues.

Lots of people were at fault. I think we want to move on. There comes a time when you stop punishing people and ask how do we build this back in a way that’s going to be safer for the future? We should concentrate on the future and positive thinking.

Let’s talk Wall Street pay. Do you think executives get paid too much?

People should be paid appropriately. We have an open society and companies have to keep competitive.

Some say big paychecks encourage risky behavior on the Street. Do you agree?

It all depends how that company was run. At Citi, the top 35 people got stock options or stock grants. They couldn’t sell any of their stock until they retired. They had to keep that position. So the only way they’re able to part with any stock before they retired was to give it away to charity.

Dodd-Frank mandates shareholders at all companies – including banks – get a vote on executive compensation each year. Last month, shareholders at Citi voted against giving CEO Vikram Pandit a $15 million raise for 2011. What are your thoughts on that?

Why should the government tell somebody how much they should get paid? The free market will handle that and it has. There’s been a big outcry about pay. That’s how shareholders are reacting. I think it’s good, that’s the free market. If you buy a share you should be able to have a voice. That’s what a vote is all about.