Try using, and servicing, an old industrial lathe or anything else in a mechanical workshop and see how quickly you can get up to speed. Repeatedly achieving me

Try using, and servicing, an old industrial lathe or anything else in a mechanical workshop and see how quickly you can get up to speed. Repeatedly achieving meaningful results, and keeping the workshop functional and clean, was someone's career. It is not "easy" and ideally requires a degree to understand materials and forces, and so on.