You have no idea how weird and wild and wonderful humans are. You overestimate them, underestimate them, and fail to understand the vast range of their complexity.
In my experience, most humans can imagine other humans as being about a maximum of twenty percent more or less than themselves on any given personality metric. So if you imagine the most charismatic person you can conjure up, realistically you’re imagining a person about twenty percent more charismatic than you. Likewise, if you imagine the dumbest person you can think of, this phantom is actually only about 20% dumber than you, because that’s the limit of your imagination.
Humans are so, so, SO much more varied than that. The smartest person alive is a hundred times smarter than you, and the dumbest person alive is a hundred times dumber. Likewise on any metric you can think of.
So don’t go into a room thinking you can predict how the people inside it will behave before you’ve met them. You will be surprised!
The Opportunity Machine 