I think one of the achievements I am most proud of is designing on my own in my early teens a constructed language, not even knowing that other people by themselves had ever done such a thing, with no one to assist me and very few resources.
Remember, this is pre-internet so I had only what books I could find in my pitiful local libraries and what cleverness was in my own brain. Still, I figured out and discovered on my own many features of language that I only later read about in real linguistics books.
Not bad for a hick with a bad haircut in a nothing town.