For me it was a discipline thing. Then a mentor of mine convinced me that not writing tests was actually okay when you're exploring something. He suggested I on

For me it was a discipline thing. Then a mentor of mine convinced me that not writing tests was actually okay when you're exploring something. He suggested I only write tests for "production" code - something I would deploy. So I routinely would whip something up, see that it works, then start a new project with tests and rewrite my experimental code. You can imagine what ended up happening - I realized how much time this was wasting, so I started writing tests to test my experimental code so I didn't have to throw it away. I got my brain hacked. Maybe that story will help someone else. :)