Never have, despite living within the same school district I graduated from currently. I don't cling to people like that. I did attend a "hey, so-and-so is back in town for a minute" party. I didn't know any of them or have anything in common with them, or even talk much.

I ran into the daughter of someone I was on the diving team with. She was nice but looked a bit uncomfortable when I said to tell her dad I said hi, and had no idea her dad even was on the diving team.

I'm just a private person. I wouldn't hate catching up with someone one on one, but I can't imagine attending a big event and doing it 50+ times in a night with people who likely haven't spared a thought for me since 1991. Maybe I'm the asshole, but I don't care what they're up to and it would be weird if they pretended to care about me.