>But the years of using screen have ingrained in my muscle memory to use ctrl-a I still don't understand how this happened to so many people. Ctrl+a is already taken, how did anyone ever use screen without immediately changing it to something that doesn't conflict with a frequently used shell shortcut?
Indeed. I've been using Ctrl-\ as my Ctrl-a in screen (and occasionally tmux). Turns out that I never use that keystroke in real life.
The guy introduced me to screen recommended it. His words were "if you're an emacs guy, having this mapped to ctrl-a is going to drive you crazy"