Facebook COO Sheryl Sandberg chimed in again, advising me to take credit and own my power. (Um, didn’t I first chide Sandberg to own her power, according to Ken Auletta’s New Yorker profile?)

Hilary Rosen, also quoted in yesterday’s Postcard, pinged me to say that years ago when she was taking the top job at the Recording Industry Association of America, she got the best advice from Jack Valenti, the late president of the Motion Picture Association of America: “”Always believe you are absolutely the best person anyone could have selected to do your own job–and then prove it to yourself every day.”

Nice. I can live by that.

And this comment came from eBay communication chief Alan Marks, reflecting on my notion that it’s OK if women don’t reach the top of corporations as quickly as men, as long as we strive for major impact elsewhere: “The end game for everyone should not only be about a single role and destination but also about each of us having the freedom to make the choices that matter to us most.”

Indeed, choice is the essence of power. Marks, incidentally, knows about powerful women: He worked for Hewlett-Packard chief Meg Whitman when she ran eBay .