Don't judge yourself too harshly if you make a mistake. Understand what caused the problem, learn how to fix it, how to detect it or, better yet, prevent it from happening again. But don't let your self-esteem take a hit. We aim to do great work but eventually everyone can make a mistake.

Even the mythical Amazon engineering teams: I never added any of these items to my cart, and this is the shopping cart I got when visiting amazon.com as an anoymous user.