While some folks invent things, others disassemble those inventions, study them, and try to make them better. Both sets of people are inventors, it’s just that one type works on big ideas, and the other type takes those big ideas and adjusts them to make them more useful. My best friend belongs to the second group. She enjoys buying electronics and taking them apart to see if he can make them work faster, stronger, or more powerfully. He can’t build a boombox, however he can take your boombox apart and make it even louder!
He never went to night classes, never got certification in Heating, Ventilation & A/C service services, yet he can break a window AC component down to its bare parts and rebuild it better than new. I’m the one who convinced him he should take money for his time, since he was fixing air conditioners for free while he could be earning some money. He works on much more than just cooling systems, but since we are in the middle of the hot days of the summer season, people are using their air conditioners, all the time, so his skills in that department are in demand just now.
In a few weeks, when the cold season descends on the area, I’m sure he will have many requests to repair oil oil furnaces and heaters. If this keeps up, he will end up with a real Heating, Ventilation, & A/C service store, which means he will have to make it legal and pay taxes for all the AC machines he fixes.