Not surprising.

I'm really bad at this. Quite a few people I actually care about, hardly anyone I contact regularly.
I also noticed the replacement of friends to a degree. There's this guy who was my best friend for many years but geographical distance has separated us quite a bit. Now everytime I want to call him my best friend I reconsider whether I should actually call him that anymore since we have very irregular contact nowadays. It's also true though that you usually behave in a very similar manner when you meet old friends again and are relatively fast back in your old behavior. I guess these wiring in the brain take a while to really dissolve and fully adapt to new friends (and in some cases, a new Windows version)...