Did you ever found yourself trying to guess the future in, say, what matters for your financial future? If you did, then you might have come to a conclusion about your possibilities and shortcomings. You might think that you can, within a certain time-frame, save an x amount of money in order to invest, but you might not believe that you can make a much greater investment y. What I mean is that you find out what you believe, reasonably speaking, you can achieve and what you believe you cannot.
We all go through this, I suppose and there's nothing wrong with it. Except that you might lessen your future possibilities as you become rational.
I think this because, in my experience, and I have been through so much change, you cannot predict the future and you cannot be sure that you are not going to be surprised today.
If I think that my financial future has been written, then I get uninterested in it, if not unhappy. The beauty of investing is to believe that the sky is the limit. If you think you can't have that, then, as I believe, you won't also have much motivation to invest, to run calculated risks, to make sacrifices when saving, etc. Trying to guess the future often results in stifling yourself.
Instead, I found out that, if I accept that my life is in constant change, that all plans suffer contingencies, and, basically, I do not know what awaits me tomorrow, then I can think of saving and investing because my gain will not be what I planed but what a world of open possibilities offers me. In fact, it's often when you stop planing that you start believing.