Definitely messenger apps that did it for me. Back in the AOL online CD days! No one I knew could type, so I had to learn myself. By the time it was taught in

Definitely messenger apps that did it for me. Back in the AOL online CD days! No one I knew could type, so I had to learn myself. By the time it was taught in HS, my habits and muscle memory weren't having it. I could type 'properly' but far slower, so I gave up. To this day I've never had a RSI from typing (and some of the marathons were crazy!), and it's rampant among 'proper' typers.