He's always bragging about how far he can jump. When leaping from branch to branch, he's constantly overestimating his jumping ability. But since he's shortsighted and also overestimates the distance to the next branch, he tends to land safely anyway.
His thoughts and actions are faulty, and still he manages quite well in life. The same goes for many poker players: They are shortsighted, boastful apes.
Actually that's not what I meant (even though in some cases I might if you hit a two-outer). I'm saying that in poker, just because you win a hand doesn't mean you played it well.
Hand ranges can't be confirmed
Let's say you think your hand is about 50-50 to win the pot against the probable hand range of your opponent. With pot odds at 3-1, you have a clear all-in call.
It turns out the opponent actually has a premium hand and you're drawing almost dead. But you hit your two perfect cards and rake in the chips from a muttering opponent.
You won the pot, but did you do the right thing? Probably not, seeing that you were way behind when the money went in. So, then, your thinking must have been faulty? Not necessarily.
Single outcomes don't contradict a probability estimate
Maybe you were correct to think this opponent could hold that range of hands in that particular situation. This time she happened to have the best hand in the range, but next time she'll have a worse hand and your all-in call will look smart.
If you're right about her hand range, folding is probably incorrect. But it's virtually impossible to confirm a hand range. Where would you find the truth about it?
Would your opponent tell you if you asked her? If she did, would you trust her? Let's be honest, most of the time most of us don't know our own hand ranges.
No right or wrong in probability
That's what's so fascinating about probability (and poker). After an event has occurred, it's usually not possible to say which of your previous assumptions were right or wrong. You make a probability evaluation, and the actual outcome can't prove your conclusions right or wrong.
You can play a hand badly and still win, but the fact that you win a hand is never proof that you played it badly - even though some pros have been known to make such claims.
Their watertight bluff is called down by some amateur in a spot where "everybody knows I would never bluff, that was a terrible call." Maybe it was, but it won the pot.
There's often no right or wrong in poker. You might just as well stop second-guessing yourself. Make a guesstimate and go with it. If your thinking is right, you'll be rewarded in the long run.