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So, toy model: imagine the brain has a single 1-dimensional happiness value that changes over time. You can be +3 happy or -2 unhappy, that kind of thing. Everyone knows when you're very happy you tend to come down, and when you're very sad you tend to eventually shake it off, meaning that there is something of a tendency towards a moderate value or a set-point of sorts. For the sake of simplicity, let's say a normal person has a set point of 0, then maybe a depressive person has a set point of -1, a manic person has a set point of +1, that sort of thing.
Mathematically, this is similar to the equations that describe a spring. If left to its own devices, a spring will tend to its equilibrium value, either exponentially (if overdamped) or with some oscillation around it (if underdamped). But if you're a person living your life, there are things constantly jostling the spring up and down, which is why manic people aren't crazy all the time and depressed people have some good days where they feel good and can smile. Mathematically, this is a spring with a forcing function - as though it's sitting on a rough train ride that is constantly applying "random" forces to it. Rather than x'' + kx = 0, you've got x'' + kx = f(t) for some external forcing function f(t), where f(t) critically does not depend on x or on the individual internal dynamics involved.
These external forcing functions tend to be pretty similar among people of a comparable environment. But the internal equilibria seem to be quite different. So when the external forcing is strong, it tends to pull people in similar directions, and people whose innate tendencies are extreme tend to get pulled along with the majority anyway. But when external forcing is weak (or when people are decoupled from its effects on them), internal equilibria tend to take over, and extreme people can get caught in feedback loops.
If you're a little more ML-inclined, you can think about external influences like a temperature term in an ML model. If your personal "model" of the world tends to settle into a minimum labeled "completely crazy" or "severely depressed" or the like, a high "temperature" can help jostle you out of that minimum even if your tendencies always move in that direction.
Basically, I think weird nerds tend to have low "temperature" values, and tend to settle into their own internal equilibria, whether those are good, bad, or good in some cases and bad in others (consider all the genius mathematicians who were also nuts). "Normies", for lack of a better way of putting it, tend to have high temperature values and live their lives across a wider region of state space, which reduces their ability to wield precision and competitive advantage but protects them from the most extreme failure-modes as well.