Learning about #Emacs 's `C-M-` keybindings made such a difference when editing #Scheme code.
I used to think surely structural editing is overrated and I can get by with just the normal movement keys, but no, being able to grab entire forms with `C-M-k` or jump around with `C-M-b` and `C-M-f` is amazing.
Now if only I could grok Paredit too... `C-<left>` and `C-<right>` suddenly doing something completely different definitely sent me into a spin a couple of times already.
