I have normal memory but my interpretation of the worst programmer I've worked with is that he had extraordinary memory and used that to write extremely tangled code but due to remembering every call site and randomly named function he thought the code base was flawless. And the expectation was that efter he explained a piece of code once then I too should have committed that to memory and then be able to recall it days later when it unexpectedly mattered when explaining a new piece of code. Failing to do that would lead to a "sigh, I'll explain it from scratch again". I don't really remember but I think he used intellij, but like a tabbed text editor. Always ctrl-shift-f "startoffunctionname".