You could have invented Fenwick trees

There's several things like that you can accidentally re-invent. I re-invented the Trie, and Markov Chaining whilst at University. What I didn't do is give them a thorough and rigorous description in any kind of publication.

That's quite a big part of the difference, I think.

There’s also a huge difference between accidentally implementing an application of something vs spotting that it is a general principle