I think I was around 13 the first time I actually heard Motion City Soundtrack, but it wasn't until I was 15 or 16 that the obsession really took hold and I really listened to them and got them and wanted to just listen to them all the time.
I think I was like 15 or 16. I don't really go to the movies though even now, so I probably would've gone earlier if I could have been bothered. It's only a 10 minute walk from my house so my parents probably wouldn't have minded.