I would very much second this advice. I've only recently started to take a more concerted effort to stay in touch with people. I was terrible in my 20s (I'm now

I would very much second this advice. I've only recently started to take a more concerted effort to stay in touch with people. I was terrible in my 20s (I'm now 35) with avoiding all the social contact that I could. My girlfriend took the opposite approach and would just go out and develop new friendships. I'm lucky to have developed strong friendships from work colleagues over the years but I feel like I neglected some of my transient friendships. That said it's never too late, it's easy to convince yourself "oh this person will never want to hear from me after all this time" but you'd be surprised. The older you get the less I find the time between meeting matters, it's the fact you're reaching out.