Two hands on the keyboard and eyes on the screen. I don't have the most fluent typing speed, but can still maybe get in 40-50 WPM.
I did a lot of writing over the years, nothing of consequence, just part of requirements for study programs and the such.
I don't do much instant messaging anymore, and I never got into texting...but when I did IMs...to keep up with 2-3 people at a time, I guess I got fast with the keyboard.
So anyway...your observation is correct. It was more by circumstance than by any real effort to be a fast typist.