First drafts are terrible. 

They start wrong, never seem to get to the point, and often miss key details of the plot. The dialogue comes across hackneyed, like a bad note from a Freshman producer. Usually, by the end of the piece, you hate yourself and the act of writing in general. 

But First Drafts don't care. They just need to live. They need to exist so that the story exists. And, most importantly, you need to bring them to life so you can kill them. 

Or, as Chuck Wendig puts in this incredibly apt diatribe:

Your First Draft Does Not Require Your Faith in It