There's a certain ritual set of behavior you can safely engage in when you talk to someone who you vaguely remember from high school but have been completely out of touch with for 30 years.
Ask about where they are living now, and discovered that most of your classmates moved more than 200 miles away from home. Some stayed in Marquette, or came back after college, or moved to even smaller towns nearby.
Ask about their family, and you will find that some of your classmates are grandparents.
Ask about what they are doing. I was surprised to find some of my classmates having had 25 or even 30 years of continuous career in the same field or even with the same employer.
I found myself mostly talking to people who I talked to in high school - as my friend Tim put it we found the "geek table" and occupied that. Some things never change, and all we would have needed was a Rubik's Cube and we could pick up where we left off.
People do change a lot in 30 years. A small handful of folks look remarkably like what they looked like 30 years ago, plus or minus an 80s hairdo. Others changed a lot, not always in a direction I would have expected.
There was a small shrine to the classmates who had died, and it was sad and surprising to see young faces and realize that you wouldn't be seeing them again, not here and not anywhere.
All in all, it was one of those parties that reminded me of the very few high school parties I went to - lots of people standing around drinking beer, a few people dancing, and the DJ playing the B-52s. I'm looking forward to the next event some 5 or 10 years from now to see how we're still all holding up.