Tests are for cowards.
Or rather, tests make you a coward. The absence of tests is really scary when you're used to the safety net.
I'm adding something very simple to an existing system. Basically a skin on top of an existing game. The system is fairly well tested overall.
But the consultant who wrote the game I'm skinning , and who did a decent job overall, didn't write any unit tests of that particular game, and we didn't perform proper acceptance tests on his delivery. Grrr... Our bad.
So here I sit fixing bugs I found after ten minutes of eyeballing the output. And I don't have the courage to touch his code without having the tests there to prove I don't break anything.
I'm a test-infected chicken.