I miss speaking with people about work in the easy way of leaning over and asking a question (hey, do you remember the name of that function to does ___?) etc. Sure I can ask on slack but it's not the same.

I mis-conversations being unscheduled

And I miss socialize "with coworkers". We're working on the same project. That socializing helps know what's going one, what each other is doing, what problems we are running into. It gives up empathy for each other tasks etc. Reading about it in various forms of online databases doesn't come close.