I have been a touch-typist since my early high school years. My mother was a secretary, and took it upon herself to teach me the skill when she saw me struggling with the increasing number of homework assignments requiring typed papers. I'm not the best touch-typist, but it has been such a help throughout my life and I often still thank my mother for teaching me this skill. I got additional practice with typing speed from fandom based chatrooms and IMing my friends. My brain works faster than my handwriting allows. I like to write and typing is the best way to get all my thoughts out before they disappear.
Although, I must say that the worst thing that ever happened to me as far as touch-typing was concerned is the rise of the chiclet/island-style keyboard. I miss the contours of the keys. It helps with finger placement.