I was fortunate to have learned to code in an environment where a lot of excellent programmers were kind enough to help me out. For example, my roommate showed me how stacks worked. It was like magic!
For me something similar. I was using lots of if-then for the program logic, and a fellow student showed me how to replace that with an array. Wow!
Another epiphany was when I was reading the source code for ADVENT (the original Adventure game). There was a comment in the listing "A troll is a modified dwarf". And voila! I discovered inheritance.