Fear takes place in an environment of instinctive associations which aren't clearly thought out, and which aren't even YOUR associations, but those your brain mechanically wires for you based solely off mechanical, genetic algorithms ... so maybe your question is more along the lines of: why does reason seem sometimes murky? Why does articulation take effort? Why must we struggle for clarity, and why must we struggle so much for it? I think this is the real foundation of and motivation behind your question.
But, if it was easy, would it be worthwhile? Would it include you, and sweep you up with it, such that when you did win through to that prize which comes only with such difficulty in this life, that it would be uniquely yours? And would you be happy with anything less?
But only after many misadventures could you answer that in the negative. Only after winning through to much that you ARE happy with and which IS your own. Among them, patience. Among them, rational self-secure clarity. So the prize is only really appreciated for what it is in the end, and only then had. It's possession and it's true appreciation are one.
Do you believe this is true?
Sometimes, being confused makes me want to cry. Maybe that tension and inner sundering we feel in the face of not knowing is not so maladaptive at all, but is quite a beautiful part of who we are that we can come to love reason so and find our safety within it.
survive long falls, so maybe don't give up too quick.