The bottom line is that the psychology of pilots invariably leads to us trying to find both our limits,
Should read: "The bottom line is that the psychology of *SOME* pilots invariably leads to us trying to find both our limits"
Every choice involves one or more tradeoffs, even if these are unknown to the pilot.
Example:
Choice: fly low and fast
Tradeoff: margin of safety reduced, risk increased
Many pilots seem to have trouble with the concept of tradeoffs.