That is why once you get to a certain level of detail people end up specialising.
That is not get what I was getting at, Chapeau. Take atoms, for example (btw, I am in no way claiming to have much of a clue about atoms).
I seem to remember that we were taught something along the lines of the nucleus being swarmed around by electrons. I also seem to remember (years later) being told "that's not really true". So why were we "lied to"?
To put the atom into a context that most people could understand (enough), to get them through whatever education system they were subscribed to.
My point was that most people can "picture" electrons whizzing around a nucleus, because they can "picture" it in their minds. But only a subset of those people can then grasp the next level of complexity, and so on and so on, until the level of complexity exceeds that which even the most gifted human brain can comprehend.
And while I take your specialism point to a degree, that is only part of the point. Collecting and knowing about stamps takes no "intelligence"; it is just an exercise in perseverance, and memory. But being an authority on stamps is probably mutually exclusive to being an authority on say, lego blocks. Not through the need for intelligence, but through sheer weight of numbers.