My short term memory is much reduced compared to my younger self. Consequently, I work in ways which allow me to reduce cognitive load and still accomplish the task. FP is a godsend for me, even if I just adopt some of its principles.

Likewise. I have ADHD and even with treatment, I feel more like a GPU than CPU. Small functions, lots of static typing, IDE for autocomplete, and lots of FP style patterns.

When I get thrown into an un-typed python codebase, my productivity grinds to a crawl, and I start having to do things like have a scratch pad with various versions to copy paste.