I was aware of the possible biases you could get as a commercial director, like being too concerned about the technical aspects of the form rather than anything of substance. If you keep working in commercials, you can get trapped in a very superficial way of thinking. I always used commercials as an exercise for filmmaking, like going to the gym.
I made commercials for corporations like Volkswagen and Coca-Cola, but I was always the one to write them, too, which was a very good exercise, because I learned to tell little stories.