I am a trained watch repair technician. In school, we were trained to never touch the movement of a watch with our bare hands, even if it was filled with water

I am a trained watch repair technician. In school, we were trained to never touch the movement of a watch with our bare hands, even if it was filled with water and any sort of dirt, and to never leave a movement sitting out in the open air to collect dust, even if it was already filled with dirt. The only reason why, it develops the habit of leaving fingerprints on parts and leaving clean watches out in the open. If you don't strive to be clean, efficient, and build beautiful products that you enjoy looking at and working on, even when they are broken or where no single person outside of you and your colleagues are going to see it, then you will start making mistakes by leaving fingerprints and broken code snippets on the side where your customers are going to notice.