somehow this thread has become focused on piano / music lessons, from my reading of Will's post, his experience w.r.t. movie roles and his mother's part in that went way beyond "go practice your piano / violin / oboe" before you hang out with your friends" being discussed here
I met Tim Patterson back in late '81 or early '82 I was working for Micropro (WordStar) at the time in San Rafael and they flew me up to Seattle. I guess we discussed porting WordStar to SCP-DOS but it's so long ago!
The point was that those commands used muscle-memory and were conceived so that the majority of editing tasks could be executed with leaving the "home" position