When I’m programming, I have a saying that I repeat to myself: “Never underestimate your ability to screw stuff up.”

It never ceases to amaze me how capable I am of messing up seemingly simple tasks.

Sometimes I get overconfident and, for example, I try to make a big change all at once without checking my work periodically. Usually I’m humbled. I end up creating a mess and I have to blow away my work and start over. I end up creating a lot more work than if I had just stayed humble and careful in the first place.

The advice that I have to frequently remind myself of, and which I give to you, is this. Recognize that your brain is weak with respect to the intellectually demanding task of programming. Work in small, careful steps as part of a feedback loop cycle. Always assume you made a mistake somewhere. Treat your work as guilty until proven innocent. Don’t trust yourself. You’re just setting yourself up for pain and frustration if you do.