Many years ago, I hoisted several (actually, many...) pints with John Candy when I was at University. He was with Second City then and they had come to school to put on a show. He was a funny guy, but by the end of the night, he was just another obnoxious drunk, just like the rest of us!
Along the same lines, I went to high school with Dave Thomas (of "Ghostbusters" fame) and had breakfast with his older brother Ian just a couple of weeks ago...
Mercifully, I don't know Celine Dion, but I am waiting patiently for call from Shania Twain~