I think back on my earlier self and realize that younger me was less aware of the big picture swirling around me then than older me is now. I'm sure older me will look back on current me and think much the same, though I'll probably not quite get why onions on the belt are no longer the fashion.
Still I'm sure that if I somehow found myself being president - past, present, or future me - I'd have a vague sense that this was an important job and that I'd better not fuck it up too badly. Probably the presidency isn't quite as important as we think it is. Leaders of other countries aren't quite as hermetically sealed off from the world is ours is. Perhaps the special importance and power of the American presidency is not quite as special and not quite as important as we think. Sure there are those nukes, but other countries have them, too. But it is important, and I'd realize that whatever resentments were swirling around my little noggin, the world didn't need to hear too much about my spats with random people or my big sads about how I didn't feel loved enough because the adoring crowds weren't large enough.
We're probably all monstrous messes on the inside, but we develop a bit of a filter to limit how much others see that. How is it possible to be a 70-year-old man - and perhaps the smartest of all men! - and not get that maybe now is not the time to get into a twitter tiff with Kindergarten Cop.