How would life be if you had not yelled in anger at someone 5 years ago? If you had not been utterly miserable 4 years ago? If you had got something you had longed for desperately 3 years ago? If you had not made one seemingly incongruous decision 2 years ago? If you had been stubborn as usual and refused to listen to reason? If you had been able to take back something you said to someone once, which made you feel terrible inside?
It would be a whole lot different...
Things that we do, seemingly so unconnected with anything else, have such a great impact on our lives. Things we wish we could take back, show their value a couple of years down the line. Something or someone you wish you could have but fail to acquire, and are heartbroken about, actually show their purpose much later when you are able to attain something much much better and you thank your stars then, at that time.
It's a very good thing life does not have a rewind button like we so often wish it did. We would miss out on a hell of a lot if it were otherwise.