"One of the advantages of a fellow like Buffett is that he automatically thinks in terms of decision trees and the elementary maths of permutations and combinations." (Charlie Munger)
Most people do not.
It doesn't appear that the majority of investors are psychologically predisposed to thinking in multiple scenarios.
They have a tendency to make decisions categorically while ignoring the probabilities.
Thinking in probabilities
Thinking in probabilities is not impossible: it simply requires attacking the problem in a different manner.
If your investing assumptions do not express statistical probabilities, it is likely your conclusions are emotionally biased.
Emotions have a way of leading us in the wrong direction, especially emotions about money.
But if you are able to teach yourself to think in probabilities, you are well on your way to being able to profit from your own lessons.
Not often will the market price an outstanding business or any other outstanding businesses substantially below their intrinsic value.
But when it does occur, you should be financially (have the CASH) and psychologically prepared (have the COURAGE) to bet big.
In the meantime, you should continue to study stocks as businesses with the idea that one day the market will give you compelling odds on a good investment.
"To the Inevitables in our portfolio, therefore, we add a few Highly Probables." (Buffett)