I went to a church school for high school and every year they have an alumni weekend for all the people who have ever graduated. We get to see all those we were close to for those 4 years. I was close to kids in grades ahead of my year and after my year of graduation so it makes it nice.
I went to my 10th and was so different (had left that church and was already going through a divorce) from everyone else I vowed I never go to another one. But I did go back years later and it was much better. I found the guys changed more than the girls did in their looks.
The one year I put together a booklet of classmates who contributed updated information about themselves and photos, kids, grand kids etc. It was fun.
Now most of us are on fb so we stay in touch. Some more than others, but it's nice.
I have no real desire to go back to another reunion except to see a few special people.
If/when I do go I go alone or with my DD as my kids went to the same school as I did. The one year my DD and I went together (drove from TN to PA to attend) and on Sat we were dressed alike! It was fun!