And no, it wasn't shame I now felt, or guilt, but something rarer in my life and stronger than both: remorse. A feeling which is more complicated, curdled, and primeval. Whose chief characteristic is that nothing can be done about it: too much time has passed, too much damage has been done, for amends to be made.
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?