Early in my career, I was afraid of making changes that could affect unexpected aspects of the system. My first job out of college, whenever I made changes, I'd read lots of code and was extra careful. Of course, nobody can ever be careful enough with this methodology, so I'd wind up breaking things. I'd feel awful for this, completely embarrassed. I'd panic and try to fix the code as quickly as possible, assuming my co-workers thought I was an idiot.
Today, I take the exact opposite approach: fearless refactoring. I refactor code without even the slightest bit of concern about the ramifications. If I break something, a test will let me know. If no test lets me know when I broke something, I don't feel embarrassed. I feel like someone else should be embarrassed.
Scary idea but maybe it makes sense