Some people have a knack for being able to look at a mechanical contraption and intuitively understanding how it works. My friend is an engineer, and when we moved to a new house he offered to help us move.
We ran into a problem of trying to get our big stainless steel refrigerator through the door of the house. We removed the door, which was the easy part of the job.
However, the refrigerator itself had handles that were attached to its own doors. Those handles kept the unit from moving through.
The handles had to be removed. My engineer friend figured out not only how to disassemble the door handles, with their various tiny parts, but also how to assemble them back together again.
I had no idea how to do that. All I saw was a mess of springs and metal pieces. As an engineer, though, he understood it perfectly.