I was exactly like that at 19, sans genius. I spent way too much time on the "fun" parts of my work and not terribly much at actually getting work done. I'd also push-back on managers pretty hard. As a result, my first two jobs involved me coding alone on projects of negligible importance.

I remember when I was 17, honestly even if I was a genius, I would have been horrible to work with.

I'm not damning his character. Or even questioning his character.

Just saying, from the thumbnail description given of his work habits - you couldn't quite call him an "engineer".