For those who want to give it a go:

#!/bin/bash
set -euo pipefail

while read -rd ":" path
do
  for bin in "$path"/*
  do
    # don't error out if there's no manpage
    set +e
    man "$(basename "$bin")"
    set -e
  done
done < <(printf '%s%s' "$PATH" ":")

when you get sick of it, hit ^Z (ctrl-z) and go kill %1. Then you get to start all over from the start next time!

Bonus points for starting a tracker so you can count how long it takes to go from "eugh, what's with that overwrought and excessively defensive bash script" to "fuck, now I'm doing it too"