Your hands are the most practical brain-computer interface you have. With touch typing it really feels like you are controlling computer with your mind - for me it's absolutely worth the time investment.

I was lucky my father prompted me to self-learnt it in high school. I have started with learning basic hand positions and technique from a book. Once I could barely type without looking, I started transcribing handwritten drafts of my school essays to the computer. Painfully slow for first few days but gradually I got to decent speed (and tidy looking essays).

Oddly, when writing documents, I still prefer pen and paper for taking notes and writing first draft. Afterwards nothing beats the power of editing on computer where touch typing is the ultimate power up.