YC founders respond to the question: What are some things that you should've known as a first-time founder but did not?

We operate a platform called Bookface for YC founders to connect with each other, ask questions, find intros, and share advice. Recently on Bookface Zach Dixon, cofounder of the gaming company Players’ Lounge (W18), asked a great question:

1. What are some things that you should’ve known as a first-time founder but did not?
2. How did you learn them?
3. How did they help?

There were so many useful answers that we’re going to share them here. The numbered answers are replies to the three questions above. The lettered answers are multiple answers to the main question...

YC founders respond to the question: What are some things that you should've known as a first-time founder but did not?

We operate a platform called Bookface for YC founders to connect with each other, ask questions, find intros, and share advice. Recently on Bookface Zach Dixon, cofounder of the gaming company Players’ Lounge (W18), asked a great question:

1. What are some things that you should’ve known as a first-time founder but did not?
2. How did you learn them?
3. How did they help?

There were so many useful answers that we’re going to share them here. The numbered answers are replies to the three questions above. The lettered answers are multiple answers to the main question...