Ask HN: Successful startups that didn't come from top-tier Universities

Reading about startups I always have the feeling that most of the "hyped" startups come from the Ivy League so sometimes it seems like it can be very difficult for someone who didn't come from that circle to succeed, specially in the Valley. Can you give any examples (or are you an example) of a successful startup that didn't come from a topnotch university? Would you mind sharing some of your story, the problems you had to deal (if any) for not being from a top-tier university?