I don't think it's (just?) the drugs. We can observe the behaviour in many types of interests. This being HN, the obvious example is programming language zeal

I don't think it's (just?) the drugs. We can observe the behaviour in many types of interests. This being HN, the obvious example is programming language zealotry. Other common examples are sports and cars. We see people walking down the street covered in car brand livery and think approximately nothing of it, and some of them will bang on about their chosen interest endlessly. I tend to think it's more like a flaw in human psychology. Or maybe a strength of our inquisitive nature that sort of gets hijacked by an almost neurotic obsession.