I have never met PG and I've never been accepted into YC. But I've listened to so much YC media that it feels like I've been a part of the program. My biggest challenge right now is that I'm learning to code and it is hard for me. One day I felt like giving up. I'm a designer. Designers can lead tech companies, right? ;) Then I heard Paul Graham's voice in my head say, "You're going to give up?!?" After that, I chose to keep going. Every day I commit to coding for 12 hrs. And even though I'm way behind in comparison to technical founders, I'm glad I didn't give up. What keeps you going?