[VonGallifrey]

Well... Self-taught means that the person learned by their own initiative, "without formal instruction or training".

Going to the library or buying and reading books is not formal instruction, and neither is watching Videos. There is no one to guide, help, or check on progress.

I could watch the entire MIT Intro to Algorithms Course on YouTube and still be self-taught, because watching that does not make me an MIT Student and it does not make Dr. Jason Ku my instructor.