I used to live with a guy who went through a nitrous phase. Gave it a try a few times, and there’s something oddly compulsive about it. You’ll do one, and then almost as soon as you come down you feel an urge to do another. Maybe it has something to do with how intense and dissociative the high is, and how suddenly it wears off.

I avoided getting hooked, and haven’t touched the stuff since, but there’s definitely a real prominent “just one more” feeling to it.