Why the name Functional Insanity?

Insanity: doing the same thing over and over again and expecting different results.
That sentence resonates with me. Why? And are we really insane?

Insanity, craziness or madness is a spectrum of behaviors characterized by certain abnormal mental or behavioral patterns. Wikipedia.

I don’t think the psychological definition applies here . We would all be insane in that case!

Is this behavior abnormal? I do it. You do it. Corporations and our government does it…. Abnormal? I think the exact opposite, it is the norm. Most of us go through the day, at least on some subjects, thinking that our same actions will yield different results. So, what to call it? I chose Functional Insanity. It’s part of our daily mental functioning yet when scrutinized looks like the behavior of an insane person.

I am fascinated why smart people behave in this way and this website is a discussion of why they do.
Why do smart people act dumb by repeating the same actions expecting different result?