As we get older and gain experience, we have to pay the consequences for our shortsighted choices. As a result, we learn to behave in a wiser, more longsighted manner. We learn to think of ourselves as a longer-running entity.
But 'I think therefore I am' presumes that self, the subject, the 'I' exists , therefore this famous saying of Descartes is tautological. My information is that very few philosophers agree with Descartes's ontological findings.