Usually I totally over obsess over something, find all the faults in it, and at that point I'd be like "meh... that's all there is". And then there's a fair share of things I don't really care about in the long run.
As a kid I had an interest in dinosaurs and now I don't really care for them. Yeah, I can still tell apart some of them, but really, there's no interest for me to read up about them. As a kid I used to have a big interest in cars, up to the point where I could make out brand and type by the weirdest things... even if it were only the front grille or such. Now, I don't care about cars and don't even have a driving license. I used to obsess over videogames a lot in my teens, where I wanted to read up every article about some games, played them a lot, had my mind on them when I was in school... don't really think that was a gaming addiction, cause I didn't care for just any game... I had my specific games I liked. That kinda saved me money all my life, cause I just could have fun with a game I had... and play nothing but that for over a year (as opposed to people who aren't hardcore gamers but easily buy a few games a year/month)
I do have my interests/obsessions that come in waves in terms of games though... but I alternate a bit between playing Magic the gathering (a card game) and currently again Warhammer 40.000 (a miniature tabletop game), both which require a lot more time and attention in deck/armybuilding.
In general I do have a lot of interests that require a lot of time... and in a way I feel that obsession doesn't really cut it.
I even feel that if I can't obsess over something... if I can't breathe and act it... I don't care for it. That might be a bit troubling for people that I have some more contact with, cause my mind will be on subject X or Y all the time... even in normal conversation. And if someone is not familiar with such subject, I might come across as making really obscure and geeky jokes... which might be perfectly fine if you'd talk to people who're into the same thing.
Me not being able to obsess over something in 48 hour non-stop sessions cause of an interfering job, caused me to feel really "lost" and I did not have a clue what I had to do with my time... cause the entire "you have to quit now, you have other obligations" really got me annoyed and disinterested... which in effect is a big problem if you're into things that cost money and energy.
I do feel that my current obsessions/interests are an interesting way to have a perspective on certain things. I can watch any movie in my collection at least once a year and have a totally different point of view on some kind of plotline... in a way it's gratifying cause that means I can enjoy myself with the same "base material" over and over again. It's like applying philosophy of your current obsession on the same matter... over and over again.
In a way I even feel that my obsessions/interests at a time were the reasons I chose my direction at university. When I had a paperround in the morning I read a lot of newspapers. I also listened to a lot of radio (mostly Howard Stern) and I thought about journalism (and had no back-up plan). Then that failed and I thought about "well, as a teen I was in computers a lot" so I enrolled in computer science, but that never sparked again.
I once thought about Social studies, cause in general philosophy, social behaviour and psychology did interest me a lot as a background interest, but there's a lot of courses I had to finish before I could even start there, thus that didn't fly. But that might just as well be a temporary thing.
Often, within 2 weeks of doing something I'll lose interest enough to not care about it and feel on the brink of depression. That's my beef with education in general. I can't imagine to study something for 4 years, keep it interesting and then have a job in that field for another 40+ years. I can't keep motivated for 2 weeks, let alone a year. That being said, I really try to avoid said subjects. I remember that after my computer science course... I refused to touch a computer for 3 weeks, after 2 weeks of class. And journalism has kinda scarred me to touch newspapers (or even care about news in general) in really small amounts.
Seriously.. I feel that an obsession has to stick or it'll scar me for life -_- and I'll hate it with vigor. Though, that doesn't mean I don't want to try things... I'm just really, really weary to trying "anything". The next best thing is obsessing over life and then hating it... with a zeal.