What an interesting question!

I have a disorder that statistically wipes out between 17 to 33% of
my memory over my lifetime.
Was that time wasted? I'm sure the ones who were in charge during those years didn't think so.

And those times I withdrew into a cocoon of fear and depression and pain? I consider them journeys I had to take in order to arrive at my
current destination. So I can't consider them wasted.

All of the people who have loved me and those I have loved, the ones
I've shown kindness to without thought of reward and the seven I pulled back from the edge--these things were made possible by all that had
gone before and all that has transpired since.

The decades I spent writing novels that will probably never be published
could never be considered wasted, for those hours spent writing were
the happiest of my life.

And the time I spent with my sons before God took them from me were a blessing that will always sooth my heart.

Wasted? Not one minute, not one second. I have had sixty six years of
being gloriously, splendidly alive. And I am grateful.