I’m ashamed to admit that early in my career I was a pretty bad employee. My skills and intelligence weren’t an issue - I never encountered a problem at work that I couldn’t solve. But my attitude was. I’d spend days lingering, and I often made my coworkers linger with me. I’d read technical articles all day long, or complain about the poor quality of the code base or the inflexibility of company policies, or talk for hours about how the whole thing would have been much better if it were written in Lisp.
Well, it was fun to read articles on my employer’s dime, the code base usually was horrendous, the policies were terrible, and the whole thing would have been much better were it written in Lisp. But none of that was constructive, or useful, or helpful to my employer or me. In retrospect, I can’t believe how incompetent I was, despite my skills and (hopefully) intelligence.