Don't mean to get too deep and meaningful, and I also appreciate it's probably a good job we don't know (the following) for a number of reasons. But I'll type it anyway ...
I sometimes think it would be good to know when you see someone (e.g. family member, friend, work colleague etc) if it's the last time you are going to see them, ever. In the context of this thread, schoolfriends.
I used to drink with a few mates from school. Gradually, that stopped happening. Little did I know around 30 years ago when I walked out pub x it would be the last time I'd see schoolfriend y. Otherwise instead of just saying 'catch you later' I could have added whatever to the rather bland default goodbye.
As I say though, it's probably more heathy that we don't know this.