We always use most of our time to predict somethings. The result of the match, the question in the exam or even the thought of someone.
Though, we can't call it a prediction. Prediction, it's accompanies with fact and data. That's why we got a bunch of dude who predict the FIFA matches, the economy of the world or even the horse race.
Most of the time we are using assumption. We assume this and that, we assume here and there. What we can is only assume something so that it will go on according to our will.
There're too many possibilities and too many IF. So next time, when you deal with something, don't make any assumption or prediction. Let your fate to decide and allow affinity to judge.