I also think the second, or external brain idea is relevant here, with reading and writing as well as tiddlywiki. We effectively extend what our brain can perceive and do buy making use of tools to store, visualise and record.
However before reading and writing we have language. I heard of a fellow who was deprived of language when young. He was still able to operate quite well, however once he was “rescued” it was difficult for him to develop language, but when he did it was difficult to recount the time when he had no language because his thinking back then was not maintained in a language.
I think we can think even without language, but language can help us think, and when dealing with more complex ideas it is difficult to think without writing or other tools.
In some areas I can’t think as well, without coding, at least pseudo code.