In my 30 years of professional programming, and even with my admittedly declining short term memory, I have never felt lost without access to versions of code f

In my 30 years of professional programming, and even with my admittedly declining short term memory, I have never felt lost without access to versions of code from 5-15 minutes ago. Not to be harsh, but I really think that this indicates some fundamental approach issue rather than a tooling problem. If it cannot be written on paper (or tablet note with pen) as rough pseudocode... or even drawing boxes and arrows for the visually-inclined, then the problem is not understood. Take what is understood and codify it, pushing the complexity and the unknowns to the edges. At least that reduces the complexity. One aid I do lean on heavily though is a REPL. Load the code and do some interactive work with it. Inspect the data, test some transformations, and then write code to do what works. That's my current approach to situations that I cannot immediately and accurately write in one pass.