"The hip quotient is a very defining one for many men," Gunn says. "But you have to reassess [your wardrobe] at regular intervals. It's different for every man—it depends on your body changing, your lifestyle changing, your work changing. I think I did an assessment at about 40."

Patti Stanger, founder of the Millionaire's Club dating service and host of the Bravo reality show Millionaire Matchmaker, points to a reasonable middle ground between dressing like an understudy for Keith Richards and shuffling around in hiked-up polyester pants.

"You have to give up the leather bombers and the Members Only jackets, yes," she says. "But it's not like you have to put on a grandpa Missoni sweater. My boyfriend's 50. On the weekends he wears Vans—adult Vans, the ones that look like boat shoes, not kids' Vans. I wanted to buy him a hoodie recently and he said, 'No, that's too immature.'"

But conquering arrested sartorial development—and then resisting the urge to regress—takes discipline.

Jean Touitou, the French designer and founder of A.P.C., is well over 50. He treats the abundance of graphic T-shirts and hoodies available to him like an aging socialite treats the dessert cart.

"Skinny jeans. I can't do it," he says. "Down jackets. I'm too old to wear them. It's not very sexy. If I were a woman or I were gay, I couldn't take the aging-rocker look. It seems it's a trend because we do not accept death, apparently."

So get a Ferrari. Get a 22-year-old girlfriend. But dress like a grown-up. To do otherwise is to undermine your dignity.

"I'm proud of my age," Gunn says. "I dress for the body I have and the work that I do and how I want the world to perceive me. I want to look like someone people trust and believe—not dress like somebody I'm not."

His point is a solid one. Self-delusion isn't flattering to anyone. Ask Dina.

Still clinging to that earring and biker jacket? Tell us your thoughts on dressing younger than your years right here.