The disappointment of a lost opportunity is as big as the expectation we placed on things we can not control.
If we do the best that we can, then that is all that we can control.
Most opportunities involve others and they are outside of our control so we have to expect nothing of others, then the disappointment is a great deal less.
However, the only sure way of not losing opportunities is by choosing ourselves and creating the thing that we want. That removes the other people factor and waiting to be chosen.
Opportunities are there for us to create.