Me, not in person. But, my best friend's family is oddly prone to it.
Her parents were in Vegas and went their own ways inside the casino. Her dad noticed some hubub over to one side & went to see what was going on (filming a movie). He started chatting with what he called "the nicest pretty lady" and chatted for about 30 minutes. When he met back up with his wife, he told her what a nice conversation he had with this "lady", and when his wife asked him to point her out, he pointed to SHARON STONE. He had no idea!
Her brother worked at an Olive Garden in Tennessee, and waited on Robin Williams... and when he was younger he worked in fast food and Steve Martin came through the drive thru. They live in any old 'regular' place, certainly not where you'd expect to see celebrities, but there they were.
My friend herself worked the help line at a software company and took a call from Barry Manilow. She broke form and said "Is this THE Barry Manilow?", to which he answered "yes, are you a fan?"... she said, "my MOM LOVES you!" LOL (not true, but what're you going to say to his face? We think you're hokey?). She talked to several famous people (well known software company) but I can't remember who the others were.
Oh yeah, my husband stood next to Kristi Yamaguchi at the luggage carousel in the airport. Said she was a snob to people around her