You learn quickly that some relationships/friendships/acquaintances are transient in nature. Some people will come back to your life, but most will not. I remember checking in on people (mostly women) from college who I was close to from anywhere to a couple semesters to up to 7 years just to say what's up, but I seemed to be the only one on that tip so I fell back from all that shyt. At first, it's surprising women you killed a lot of your time with one semester and went to school with for both high school or college you probably won't talk to much again, but that's how it is.
There's some friends also that fell to the wayside, but I know I got a real good circle around me and whoever hasn't made it this far probably ain't worth the time.
TRANSIENT is the key word here. Those friends you can meet up with randomly and its like picking up where you left off are not transient. Those friends you go out with regularly aren't transient. Family isn't transient. Everyone else though...