Oh, man, somebody actually thinks the "excellence" part of the curve isn't plagued by things like how much easier is to spot all the ways things can cause problems down the causality chain (guess what, when it's easy and natural to, for every action being considered, see 3 or more links down the chain of possible consequences, one always finds risks and negatives) and associated tendency for paralysis by analysis or simply the being quite abnormal compared to most people.
In my experience the perfect spot of the curve when it comes to felling good about oneself in this one human characteristic is to be what I call an "entry level genious" - a barelly into the genious IQ, just about intelligent enough to feel more intelligent than th majority of people one encounters but not so intelligent one is aware of the limits of intelligence and how little even genious adds to one's overall capabilities (and example of this would be Elon Musk), or in other words, on what is pretty much the peak Dunning-Krugger point of Intelligence.
(All the best salesperson types I've worked with were at that sweet-spot: intelligent enough to find it easier to outsmart most people and have high self-confidence but not enough to understand the potential problems and limitations of what they're selling)