After binge playing The Sims 3 (c'mon son you know you still play The Sims 2) you look at the clock and realize it is 5a.m. What?! But you were supposed to go to bed at 1!
That game is addicting--yes. But the computer is the culprit too even when you're not simming it up.
Computer light lowers melatonin levels (moonlight & streetlights are better). Lower melatonin causes insomnia!
Bottom line? Don't use the computer before bed.