I think it helped also TPAM that I am the same age as Mason at the conclusion of the film and in similar circumstances (i.e. heading off to college/university) It was also nice to relive the past twelve years through someone the same age. Like, while my parents could relate to being 6 years old, they couldn't relate to being 6 years old in 2002, like I do. Same for being 10 in 2006, 15 in 2011 etc. The pop culture matched up with my ages perfectly, so I think that's why this film seems to be resonating most with people aged roughly 17-19

Edit: Too slow
TPAM does also
In fact, everyone on this page so far seems to have a .gif avatar