Been there too, walked out last year with the same mess.

Cemented groups can wick moisture into the seam, so keep temps low.

That part about being able to flip through pages and find what you need from memory really hits. Grease smudges on a certain page, a corner folded down where the torque specs are, that stuff builds up over years and it works like a map in your head. A screen doesn't give you that, you can't feel where you are in a phone the same way. The old guy probably knew exactly which page had the wiring diagram he needed without even looking it up.