Everything interests me, superficially[1]. Most of it is useless except for playing trivia games.
If I were a FU-rich autodidact that wouldn't be a problem but I'm a poor schmuck with a family to support.
My brain is so full of interesting stuff and tangential thought that there no room for focused attention on anything mundane enough to count as useful work (though I'm sure with an equipped workshop/lab and a couple of years I can turn one of my book-of-ideas concepts to something useful for mankind).
Don't we \have\ to do what gives us a living?
[1] superficially perhaps isn't the right word, the minutiae of everything is infinitely interesting too, more that things are only interesting temporarily, which leads to flitting about across diverse subjects.