The dark bag part is right but the respooling itself doesn't actually need total darkness, most films are fine with a little light as long as you're not pointing a lamp at them. What really matters is doing it by feel and keeping the spool tight so the film doesn't telescope or get scratched. Your neighbor probably meant that part, the habit of trusting your hands instead of your eyes. Either way it's one of those things that clicks once and you never go back.