Having focused all of my time learning CG the best lessons I learnt about outside of CG.
What was like a really punch in the face for me is when I learnt that professional artists in oil painting medium would spend 10 hours per day for 3 months to finish a work. In my mind this looks like a ridiculous amount of time spent, but is really what makes these paintings in terms of quality outperform any equivalent in the digital medium. (Though can’t compete in terms of speed and multiple iterations).
Also another huge punch for me was after watching Japanese manga artists, working with pencil eraser and ink. In their livestreams they would just simply cram page after page without saying a word (mostly perhaps management of energy). Imagine now doing this for days and months up to producing an entire 500 page book full of drawings along with story.
These are some examples that can explain the meaning of discipline and time. Someone only needs both attributes of discipline and time up until reaches a reasonable level of mastery (up to a point that it can pass certain characteristics on how it looks) and is able to produce a significant volume of work.