I went next door for lunch to the fancy cafe that sells overpriced (but yummy) sandwiches to rich people here in Beverly Hills. The boy working the counter looked at me kinda sheepishly and said, "Ummmm... are you an actress?" I think I may have actually blushed (this doesn't happen often) and said no. (Well, I may not be an actress, but I played one with my last romantic entanglement...)
That's the thing in LA. It's so full of not only A-list celebs, but people who have done commercials here and there, had recurring roles on network TV shows, or maybe even have done a few movies. And then there are the musicians; alot of the time, you just aren't too sure of what they look like anyway. So there is a huge number of people in this town that look really familiar, but you can't place them, exactly. You wonder, "Do I know that guy from high school?" or "Did she work in that coffee shop near my old job?" when really you know them from an MCI ad (or if you live in the Valley, a porn video).
A good friend of mine was once horribly embarrased when she was assisting a customer and she said, "Do I know you from Berkeley?" and he said, "I don't think so." He handed her his credit card and it was Zack de la Rocha from Rage Against the Machine.
This has happened to me a couple times, and it's always embarrassing, but what can you do? I've made a fool of myself in front of some guy from the Gilmore Girls, Brad Beyer of Third Watch, Shannyn Sossamon, Drew Carey (he didn't have his glasses!), AJ Benza, and that chick from The Blair Witch Project. And more that I just can't remember because... well, they aren't so famous.