Earlier quoted context omitted.
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 the big coin drop was arrays. That took a while.
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.