I once knew a man who worked as the quartermasters office of the South African Railways.
He was the railways and in particular old steam engines he could tell you all about the different engines the gages in the cabin of the trains the diameter of each engines boiler, the type of rails trains ran on the different tracks.
He even had different scale models running on tracks in his home.
Trains we’re his passion and he enjoyed every working day of his life.
He would go to the foundry where the undercarriages of coaches were been built and work on the foundry sales Rep to get a better price.
If you have passion you can sell clay bowls to nuclear rocket ships (and everything in between) if you have passion for what you are doing.
True a certain amount of knowledge is required, but nothing exceeds the requirement of passion.