It’s a recurring thing because programing at its fundamental level is extremely simple. If you have variables, conditionals and loop/goto you can do anything. It’s pretty easy to learn the basics and get much more empowered than you had any right to be.

Armed with such power, you will build a slow, unreadable and unmaintainable mess, but you don’t know that yet, because it’s all working after all.

But as your lines multiply you begin to misstep on your own code and wonder if there’s a better way to do this. And you then stumble upon data structures, functions, classes, etc.

The self-taught road is always more or less like that.