Ha! I started my career in a company where I had to pump out custom web apps as fast as humanly possible. The apps were successful, and then I had to maintain them for several years. That's where the real learning occurred. I learned the cost of every one of my shortcuts and poor design decisions the hard way.

Many years ago, some famous developer said, "Always write your code as if the person who's going to maintain it is a violent psychopath who knows where you live." As I fixed my poor design choices one by one over endless late nights, I sometimes felt the anger of a violent psychopath toward the former, ignorant me who had stupidly plagued current me with all these problems.

When you learn the hard way, you know exactly why good design decisions are considered good. In later jobs, one of my fundamental goals for every new project was "I never want me or anyone else to have to answer a 3 a.m. call about why this system isn't working."