I recorded my first midi from the controller earlier today. Prior to that, all of my note entry was with the mouse. (I'm transitioning from MuseScore / soundfont to Reaper / libraries.)
I don't have a performance background (played tuba in elementary (primary) school and that's about it). About 7 years ago I came across Rosegarden while doing a Linux install (to make it worse, it was Arch). In a moment of supreme hubris, I thought to myself, "I have a master degree in chemistry, how hard can composing/producing music be?"
I've since earned some humility and taken a year of college theory. Composition has been almost a visual activity. I use playback all the time, but the initial notation entry with the mouse, visual, sort of.
So, this morning, I have a controller that I mostly use for sound design preview. I stumbled on a short sequence that I liked, so I learned how to record midi. I even used a black key! :)
So, today I had my first glimpse of the value of improvisation for composition.
Thank you for the topic and the other answers. It is good learning how other people do things.