I don't know about celebrities "forgetting" their underwear, but I think they make a conscious choice not to wear underwear so they don't have panty lines. I love Anne Hathaway (the latest to have a pap get a shot of her coochie), and don't think any less of her, but she should be more careful when getting out of a car while going commando! Granted, sometimes when not wearing undies, you can forget you're not wearing them (trust me, I know), and frankly, I think the paparazzi are too aggressive and opportunistic. This only happens to women. Most men don't wear dresses, and those that do aren't usually big celebrities with paps all around them.