Today is Valentine's Day, but it is also the 61st birthday of Stephen Schwarzman, co-founder of the Blackstone Group, one of the biggest and most successful private equity firms in the world.

Why is that worth noting?

A year and a day ago, hundreds of the best and brightest in finance, politics, and the arts gathered on a cold, wet night inside the Seventh Regiment Armory on Park Avenue in Manhattan to celebrate. Guests ate lobster and baked Alaska, Rod Stewart entertained, and Patti LaBelle sang "Happy Birthday."

It was that $3 million birthday party—given by himself—that soon became a symbol of private equity's new power and its self-indulgence. Schwarzman soon became, as James Stewart in a profile in the New Yorker put it, "the designated villain of an era on Wall Street."

Much has changed since that night. Washington lawmakers called for changes in the way that private equity is taxed, although nothing has come of that. Deals got bigger—and then they seemed to evaporate completely amid a credit crunch that dried up financing. By year-end, some deals had collapsed. In June, Blackstone went public at $31 a share to much hooplah. Today, its stock price is down 43 percent.

So perhaps it is not surprising that, according to the New York Post, "Schwarzman plans to celebrate his 61st birthday with a low-key evening at home with his family and a few friends."

Haven't sent a card with your birthday greetings yet? Send one from Portfolio.com.