It's interesting how this workflow appears to almost offend some users here.
I get it, we all don't like sloppy code that does not work well or is not maintainable.
I think some developers will need to learn to give control away rather than trying to understand every line of code in their project - depending of course on the environment and use case.
Also worth to keep in mind that even if you think you understand all the code in your project - as far as that is even possible in larger projects with multiple developers - there are still bugs anyway. And a few months later, your memory might be fuzzy in any case.