Here's an in-person card I've had for quite a long time. In the early '90s, when I was living in Houston, my dad took me every year to this big card show in Houston. It wasn't quite as large-scale as "The National," but it was pretty close. A massive convention hall was filled with dealers, and there were plenty of autograph guests, and there I was at 12 or 13, with a very limited budget.
I did have a local card shop that my dad would drive me to every now and then, so I didn't want to spend it all on packs. What I did decide to throw down some money one, however, was an autograph. I was pretty young at the time & didn't really understand too many of the nuances of the game, but there was one player from the Astros there, who I understood to be a good player: Craig Biggio.
While I know that I did get the card signed in person, and I do remember specifically purchasing this 1992 Topps Gold card specifically for this purpose, I don't remember a single thing about my interaction with Biggio. I'm sure me, being a shy, awkward pre-teen walked up to the table and said "Hello," asked him to please sign my card, and then thanked him before walking off. I'm sure he was extremely nice and had a big smile on his face, because that's who he is, and that's what he does. I just can't remember it for sure.
I also ended up purchasing a small plaque to hold the card. Even back then, I wanted to proudly display my unique piece of athlete interaction. I guess there are some things that don't even change 20 years down the line.