as a philosophical answer, yeah, the infinite hypotheses @Simone_De_Beauvoir mentioned are the way it is, think of the infinite universe where every possibility is being generated at any given moment but you are only aware of “this” one.
practically you’re more likely to start from the outside with a large “bubble” of possibilities and work down to a small pool of “likely” outcomes, when needing quick answers. 1+1, well you know it’s 2 not bluejay and it doesn’t take you long to come up with the answer because brain is able to do this with great efficiency in some instances. and yes you do learn from your mistakes as evidenced by how quickly you come up with the right answer.
when considering a protracted course of action on the other hand many times you start with limited information and have to hypothesize against potential variables that may come into play. scientific method attempts to simplify the question and limit situations to as few variables as possible, if your hypothesized conclusion turns out to be incorrect you go back and do a failure analysis to determined what happened and what you didn’t account for. this data does add to the collective as evidenced by the speed with which you are able to narrow down the variables the next time around.
in life of course you can’t count out all the variables so you cheat and weight them as to how likely you think they are to happen. if I run a red light a consequence might be a plane crashing into me, but i weight that much less likely than being T’d up by the cross traffic, so I decide to not run the red light, not bc the plane might kill me but bc the other cars might even though both are possible.
so, can you “know it all”? nope, but you can reasonably consider likely outcomes based on your knowledge and make an educated guess, even if you only take a second to do it. And next time, assuming there is one, you’ll be better equipped to predict the outcome because of what you’ve learned since your last go-round.