Now presenting: Michelle Obama's closet

Most of us figure the Smithsonian will never exhibit our clothes. It’s not as if it’s putting on a show called “Sweat Pants of the Middle Class: A Retrospective.”

But things are different if you are Michelle Obama. There she was March 9, watching as the Museum of American History unveiled a display featuring one of her dresses.

It was her inaugural gown, that white one-shouldered swoosh by designer Jason Wu. You’d figure that by now she’s used to being a celebrity. But she said she was a little embarrassed, and, truth be told, she looked it.

“I’m not used to people wanting to put things I’ve worn on display,” she said. “All of this is a little odd, so forgive me.”

IN PICTURES: Michelle Obama's fashion

Many first ladies have found the role of national fashion icon to be both exhilarating and a pain in the bodice. One moment barely anyone (definitely not Joan Rivers) is looking. Then – whammo! – suddenly you’re in the White House, and your outfits are a subject of fascination.

And you can’t win for losing. You’re too glamorous (Washington is not Hollywood!) or not glamorous enough (Washington is not Dubuque!). Thus Nancy Reagan, a former actress who knew how to dress elegantly, got in trouble for taking fancy duds from her old pals. Rosalynn Carter took flak for wearing a previously used outfit to Jimmy’s 1977 inaugural.

Mrs. Carter wasn’t being cheap. She’d worn the sleeveless embroidered coat over a blue dress to her husband’s first swearing-in as governor of Georgia, and she wore it again for sentimental reasons.

Maybe Edith Roosevelt, Teddy’s second wife, handled the pressure best. Weary of reporters asking for details about her clothes, she deputized her stepdaughter, Alice, to describe the dresses to the press.

Alice knew her stepmom wore only a few outfits. But she described each one differently each time it was worn, calling it “sky blue” one time and “periwinkle blue” the next – so that the media thought Edith had a much more impressive wardrobe than she really did.

Reporters. They’re so gullible.

IN PICTURES: Michelle Obama's fashion