Also important is touch typing. I’ve been coding for about 8 years now, and only learned to touch type last year (after several false starts). While I’ve seen dramatic improvements in raw productivity, it’s the less tangible benefits that have surprised me.
I find I’m more likely to learn and use the keyboard shortcuts discussed here. My ergonomics are better. I feel more comfortable with lightweight, keyboard-centric text editors. I am much quicker in a terminal now which I find more productive than gui based shells (particularly on unix/cygwin).
My coding has improved too; cumbersome things like documenting and unit testing your code become less of a burden. I learn faster because I can prototype code quickly and feel out language features. Interactive shells like irb become a playground where you can introspect the code at close to thinking speed.