There are a bunch of contradictory arguments about the value of living in the ‘now’, being grounded, being present for what one is experiencing, as opposed to dwelling in the past or fantasising about the future. Presence is valuable, but so too is recognising one’s past mistakes and learning from them, and having hope and ambition to move forward into a better future.
I have a dreadful memory, which I usually enhance by dwelling on past mistakes and slights, exaggerating them, pulling out each minute facet of a moment like a Cubist, searching relentlessly for clues to why I am the way I am, why other people act in certain ways, why things went down the way they did. I am notoriously (occasionally gloriously) past-oriented. I ignore the future as a place of unknown terror, and, from a certain viewpoint, I’d say I waste the present.