Emmett Shea​r, who co-founded the live streaming video platform Twitch, thinks back to his early days as an entrepreneur, the lessons he gleaned from his mentor, and what he does now to inspire others. --As told to Nick Hawkins

I'd just graduated from ­college, in 2005, when Kiko Calendar, a startup I founded with Justin Kan, was accepted to Y Combinator's Cambridge, Massachusetts, accelerator. There, I met Paul Graham, co-founder of Y Combinator--and the man who would teach me how to think bigger, and to inspire others do to the same.

Paul is the sort of person who can make you feel, after just one conversation, that your work is the most important thing in the world. That's his superpower--along with an ability to reimagine ideas in ways others never would. One day, in Paul's office in Cambridge, I was telling him about Kiko's strategy. 'You know what you should do?' he said. 'You should make Kiko a programmable calendar, so hackers can create custom event types, and triggers. That might be the first step toward a new operating system built around time.' My co-founders and I weren't ready to execute on that dream, and ended up auctioning off Kiko on eBay for $258,000 after Google Calendar launched. But Paul's can-do attitude has stuck with me.

He taught me the importance of inspiring people to believe in themselves, to have big ideas, and what to do with those ideas. Now, when I meet with Twitch teams, my goal is to help them see how what they're doing is important for Twitch--and how it could lead to something bigger. If a team feels like they can take over the world, I've done a good job.