My favorite is this: 16 years ago or so my friends and I (high school) ran into Steve Berra while we were out skating. He was super cool, handled our heckles, and invited us to the finals of BATB 2. "Just email me a few weeks before."
True to his word, a few months later he emails us tickets (literally like 20) for entry and we convoy up to LA with no real idea where The Berrics is, just a general direction (keep in mind this was 2008/2009, IPhones had just come out the year prior, so while we had the address, we couldn't just map ourselves there). We drive around what we think is the general location to no avail. Just as we're about to give up, we decide to ask some super hipster looking guy riding by on a fixed gear. "The Berrics, like the skate spot? Yeah, I'll show you, my roommate goes all the time, you guys ever heard of Heath Kirchart?" Turns out he was Heath Kirchart's roommate at the time. He showed us the way. Iirc it was under some bridge or something at the time, super random/hard to find. So not technically a pro, but the most memorable for me.
Some other fun memories from that night: PRod being super cool at the BATB - one of our younger friends asked him for his autograph (not seriously - we were 13-17 year olds who thought we were hot shit) and he took off his Mountain Dew hat he won the game in, signed it, and was super nice. That Boosh dude got thrown out for getting too drunk and yelling at Luztka, "Nice Fedora!" on repeat whenever Lutzka skated. David Loy (beanie and cast version) mean mugging us for no reason in the meal line. Salman Agah was working the entry tickets and was pretty cool, also served some pizza iirc. A few friends from that trip ended up getting sponsored, and at least one is now pro, but at the time, especially being so young and removed from everything, it was just awesome.
Here's one more super funny random one: a few years back I worked for Amazon corporate, and another engineer on my team was roommates with Dennis Durrant.