In a way this also applies to creating things in your spare time. Many side projects I worked on ended in a dusty archive. Just because I wondered to much about possible problems.
This is my first post here and I would like to add that it's quite interesting how just reading HN slowly changed my approach to actually try and create something.
Thanks.
He basically says: Do not let fear overwhelm you. Just do it. Listen to paying customers. Then just do it. And drugs.