Often success is nothing more than putting yourself in a position to take advantage of unexpected opportunities.
A lot of people waste time trying to accurately predict the future when they could ensure success by positioning themselves for multiple possible futures.

This came with the kids.
They can't predict what they want to do when they grow up, but they can position themselves to have more options by taking harder courses.
They can't predict what they will need money for in the future, but they can spend less than they make.

One nuance ...
Proper positioning allows you to take advantage of all opportunities.
For "regular" opportunities, poor positioning is a form of self-sabotage.
I try to teach the kids this lesson with exams. How do you put yourself in the best position possible?

To put yourself in the best position possible, you have to study, sleep, eat healthy food, etc.
Unexpected opportunities tend to have asymmetric payoffs. If you are in a position to take advantage of these, you get a non-linear payoff.