It strikes me that this may be one of the differences between youth and age: when we are young, we invent different futures for ourselves; when we are old, we invent different pasts for others.
You grew old first not in your own eyes, but in other people's eyes; then, slowly, you agreed with their opinion of you.
When we're young, everyone over the age of thirty looks middle-aged, everyone over fifty antique. And time, as it goes by, confirms that we weren't that wrong. Those little age differentials, so crucial and so gross when we are young erode. We end up all belonging to the same category, that of the non-young. I've never much minded this myself.
Though why should we expect age to mellow us? If it isn't life's business to reward merit, why should it be life's business to give us warm comfortable feelings towards its end? What possible evolutionary purpose could nostalgia serve?