For me it was Jeff Kinney. I was meeting a different author I love, but there wasn’t enough room downstairs and we had to go up. Turns out that’s exactly where Jeff Kinney works! He’s the author who got me into reading so I thought that was so cool
Paul Walker, at blockbuster in Santa Barbara 2008. He didn’t have his membership card, had to look him up by his driver’s license. I had no idea who he was, my co-workers were freaking out and asked me what his license looked like. I didn’t pay attention at all and couldn’t remember any details. My guess he probably appreciated being anonymous to me.