That's quite opposite for me, I write code with lots of tiny errors (most of them 0,1 based array sizes or not understanding how API works), so I test as much as possible. But tests true value is regression testing. I can refactor something, and test knowing that if I messed something up, test will flare up.
I still try to avoid errors, but it's pretty much nigh impossible.
I always write good code, but somehow that code turns to shit after six months, and I promise no one touched it. So, I guess I don't need the tests when I'm writing the code but I need them badly when I maintain it.