One approach to decision making process in situations where you can't be 100% sure, not just in poker but in general, is to take into consideration all the information you may have at your disposal and base your actions upon this information. You can for example:

Check the weather forecast before going out >>>> Look at the sky and clouds>>>>> Take a rain coat with you- or leave it at home. 

There could be more at stake: you're transporting some kind of material which would be destroyed by water, in which case you would be wrapping it up in a waterproof case of some sort, or choosing to transport it another day if that's an option. You could also 'have a feeling it's going to be all right'- well good luck with that.

Everyday we make choices based on different variables and draw our conclusions and actions. 

Poker is a game of many variables. The villain type, the history of the hand, the ranging of the opponents per position, the perception the opponents might have of you, the skill level of the opponents you might find in a buy in level, so many factors and of course all the statistic calculations and maths part. This is one reason why the main answer to most poker questions is: it depends. It depends on you, on the villain, on the board texture, on the type of game, on the stakes, on the actions taken in every street, all these factors and more, plus of course the positive and negative variance- which you have no control over. You do have control over the decisions you take.  

Some decisions are easier than others. You are in the SB with 12 BB in a turbo MTT holding Button with a big stack opens 3x BB steal. You shove. I don't think there is any other way to play this hand, regardless of who the player at the button is. Or is there? Would you call and perform a stop and go? 3bet? Did he fold to a re-steal shove before?

How about this: You are holding the same  in the SB, only its a final table, there are 5 people left, you are the second biggest stack, the small stack utg shoves, the bigger stack UTG + 1 shoves on top of it, another small stack calls and is all in . You and the BB who has only 4 BB are still to act in this 3 way all in. Still a call? AA 4 way is going to hold? How about the prize jumps? There will be other variables to consider.

It is interesting to notice that most poker decisions are borderline decisions.  Yet, I very often come across, in forums and poker related subjects all across the internet, people (who I assume are beginning players) who have fiery discussions defending very strong opinions about how a hand (or strategy), often by other people,  should or should not be played. They often have different points of view and are very certain that their point of view is the right one. 

That, my friend, is a leak.  An ego related leak. The leak of certainty. It blinds you from opening up your views and accepting other perspectives. It blinds you from learning.