Relearning your default keyboard layout, after 15 years of typing on Qwerty, is a very strange experience. I decided to learn Colemak to combat my RSI. After a month of hard work I can type on either keyboard layout, but sometimes my brain decides it wants the other layout, and for a confused few moments I type gibberish. I'm sure this will resolve itself with time, but for now, it is very strange experience. Somewhat like learning to walk again after biking for a long long time.