She has a past. He has no future.
When they say “love is blind” they must have been talking about Amy and Ben. Amy is a beautiful young woman with a mysterious past. Ben is a scruffy slacker, whose only ambition seems to be avoiding growing up. However, Amy sees something in Ben that Ben doesn't see in himself, which gives Ben the confidence to make something of his life. The power of love shows Ben that being a grown-up isn't such a bad thing after all.