Comment by QuercusMax

Music is the same way, especially with improvisation. When you're improvising, you don't make stuff up entirely from scratch - you glue together all the little bits you have in your toolbox to make something new. That's why we endlessly practice scales, arpeggios, learn new songs, copy others' licks, etc.

Why do you think half the keyboard/organ solos in classic rock songs sound like jazzed up versions of Bach and Mozart? That's what they had learned as kids or in music school before going on to make rock and roll.