The other way around happens more often for me. I lose respect for some people as we age, their inability to get their act together, or disapprove of parenting styles (and watching their kids suffer from it).

This has happened to me several times.
I don’t think any of us want to be judged by our high school personas.
I’ve forgiven many, and been forgiven by even more.

I haven't kept in touch with my former classmates, but I'm sure it can happen.

I have not but I do feel like I would now understand what made someone the way the were when we were younger .. home life, financial situation, etc

Every have someone that you didn't necessarily like when you were in HS or college, but turned out to really like them when you cross paths later in life?