Growing up I lived in a fairly affluent area where a number of celebrities lived. They also made a lot of movies, TV shows and commercials nearby, so I met a number of celebrities.
I went to grade school with Bob Denver's (Gilligan) daughter and high school with Heather Locklear.
I worked at a gas station in high school and met a number of other celebrities as well. Robert Young, Dean Martin, Tom Selleck, Hal Linden, Dick Enberg, Katherine Bach, Lynda Carter and Sophia Loren. Sophia Loren was stunningly beautiful and a very gracious lady.
Later on, I met President Bill Clinton. Say what you will about his politics, when I met him, he was a very nice man, engaging, kind, concerned, and I felt like we were good friends after a brief meeting and conversation.
I have personally interacted with hundreds of people that are considered celebrities. Even with some before they were well known. (think - Johhny Depp when he was on 21 Jump Street)
Some have been huge, huge stars. Some have been great to interact with and some haven't.
I've had some that were an embarrassment to what being a human is to ones that are shining examples of being full of humanity and humility.
I played with Allison Krauss when we were both in High School, literally at Band Camp. I know a lot of people in music who've worked with some big names. And once Kenny Rogers recorded at my studio.