In 2007, Drew Houston flew to San Francisco determined to find a co-founder for Dropbox. At the time, it was just him. No backers. No team. On a friend’s advice, he walked into Y Combinator’s offices unsolicited to talk to Paul Graham about finding the right person. It didn’t go well.  “It wasn't a great experience, coming in unannounced,” Houston recently told students in an exclusive Dorm Room Fund interview at MIT. “Getting into Y Combinator is like getting into a great school. So imagine having your two minutes with the dean of admissions and them coming away thinking you’re an asshole. That plane ride back was the worst. No co-founder. Lower chance of getting into YC. I was panicked.” The good news is, early founders can turn things around. Soon after he thought it was all over, Houston teamed with fellow-MIT alum Arash Ferdowsi and made it into YC. Today, he’s led Dropbox to nearly 200 million users — and the company’s growing faster than ever before. This hasn’t been a piece of cake, but Houston’s rocky start did teach him to forge ahead and throw out assumptions that discourage many would-be founders. Looking back, he recommends six strategies that helped him cut through the fear, drown out the noise, and make it happen.