'Life' would not be a learning tool without missed opportunities. There are two types of opportunities. There are the ones that we create, ourselves (meaning hunans), and there are the ones that God creates. The opportunities that we create are, normally, time based. They are, normally, centered around things like; youth, chance, cycles, etc. The other types of opportunities are created by God. These opportunities are not, normally, dependent on time (I keep using the word 'normally' because there appears to be an exception to every rule). God's opportunities may come at anytime. Even when you think that the opportunity is no longer possible. Yet, 'Is there anything that God can not do?'
Many believe that if, and only if, we live a certain way or do certain things, we will 'catch' God's opportunities. But:
Who hath saved us, and called us with an holy calling, not according to our works, but according to his own purpose and grace, which was given us in Christ Jesus before the world began,
So, we are saved by grace, not by our works. Because of this, God's opportunities may come until you 'catch' it.
So, opportunities, that we miss, are really opportunities that we shouldn't 'catch.' But, like jumping rope, God's opportunities comes back around. Yet, if you miss all of your opportunities, nothing may come back. Unlearn.