When working in large codebase, you come across something that doesn't work for you. You regret for your lost time and curse the person who wrote this bug. This stupid bug! You quickly make the "fix" that works for you and you are tempted to check in your fix so the world knows how smart you are. But behold! Think for a moment why this code worked for someone else. It must've worked, in no matter how niche a path, for someone to have checked in that code. And yet, it didn't work for you.