This is great advice. YC hammers home hard the point about not "playing" startup. You should be spending most of your time building your product, talking to use

This is great advice. YC hammers home hard the point about not "playing" startup. You should be spending most of your time building your product, talking to users, and selling (or some variation thereof depending on your market). If you're not doing one of those three things, you're probably wasting your time.