I was trying to be a little vague, I guess for the sake of simplicity and identity because of how complicated it is -- yes I am very close to this person and it affects me intensely because I am expected to be as interested or involved with this "thing" as this person is. And when I'm not showing the same level of interest, this person vacillates between hostile and depressed. This person's whole outlook on life depends on this "thing". You could say it's an extreme, obsessive form of a hobby. I liken it to a child who likes to play Monopoly with their friend, to the exclusion of any other leisure activity, but wants to play with real money, and wants to dress the part of the banker, developer (whatever, this is just an example), and expects you to do the same. And can't enjoy the game or their life if it's not played to their exact specifications. They also collect any and everything that has to do with Monopoly. They will call you during the day to ask about
Monopoly and it's a rare day when the subject of Monopoly doesn't come up.
If you want the details, let me know and I'll email you privately.
(I guess I'm just feeling overwhelmed with my life lately -- three kids, one of which has a chronic disease that requires surgery in a couple of months, two of the kids with ADHD one of which is extreme, a spouse with unmedicated ADHD and dizzy/nausea spells with a history of blacking out while driving, and my own anxiety/depression.)