I've had this problem from both sides. It's difficult to choose a course of action or to know what the "right" thing to do is. I end up just sending random messages to people anyway, figuring they don't have to reply or even read them but the fact is whatever it was made me think of them and so I send it. There are probably a bunch of people who are all "wtf is up with this person, why do they keep sending me random messages even though I never reply?" but I've kind of taught myself not to care. Kind of. I either don't care or I have a panic attack after hitting send. It's random.