Unlike some of the time-travel movies I love, like 'Primer' or '12 Monkeys, ' 'Looper' is not about time travel. It's about this situation that time travel creates and the people dealing with that situation. So narratively, the big challenge was to have time travel get out of the way.
I mean, the first 'Back to the Future' is kind of a perfect script, I think, in terms of handling time travel the best. It depends on your definition. To me, that means it effectively uses it in the story.
Teen movies often have an unspoken underlying premise in which high school is seen as less serious than the adult world. But when your head is encased in that microcosm it's the most serious time of your life.
I do love science fiction, but it's not really a genre unto itself it always seems to merge with another genre. With the few movies I've done, I've ended up playing with genre in some way or another, so any genre that's made to mix with others is like candy to me. It allows you to use big, mythic situations to talk about ordinary things.
Hopefully with each thing that you do you're learning something, you're growing, and you're pushing yourself a little harder in some way or another. So I think you'd be in real trouble if each new thing that you create didn't feel like 'Oh, wow. I feel like I'm doing something a little different this time.'