This piece reminds me of another article musing on the necessity of manual memory: https://numinous.productions/ttft/#how-important-is-memory.

That article articulated the reason slightly differently, arguing you need to hold multiple concepts in your head at the same time in order to develop original ideas.

Still, I'm not sure you have to remember everything, but I agree you have to remember the foundational things at the right abstraction layer, upon which you are trying to synthesize something new.