In an uncanny, almost freakish coincidence, our cat Bella, littermate to the late lamented Zee, has died of the same illness (lymphoma), almost exactly one year later, i.e., during the recent holidays, which are already horrible by nearly all measures, at least for me.
So, first off: Rest well, beloved Bella. We miss you.
I've just noticed that I am coping with my devastation in a way that replicates the premise of my first novel, Bigfoot and the Baby. That is: we shop because we grieve. I suspect I've bought more unneeded items for myself in the past 24 hours than I did all last year. And, sad to say, these purchases somehow make me feel better, if only temporarily.
Notions of "filling the void" come to mind, but seem inadequate, as an explanation. Perhaps there's an illusion of control--I find something I want, I buy it, I own it--that eludes us when a loved one is ill or dying. When we shop, we complete a concrete transaction with a gratifying result. There's no helpless guessing what might happen if we make one choice or the other; and if we don't like what we bought after all, we can usually return it (or the consequences of our mistake are usually minimal).
But the grief we feel may be more inchoate, which was an underlying theme of Bigfoot. Though I'm not religious, I believe Judaism and Christianity capture this feeling well with the story of the Fall. Our lives are rooted in a tremendous sense of loss, of reaching for that paradise we can never quite envision, let alone regain. Every actual loss resonates with that fundamental condition, making grief seem both bottomless and holy.
What evolutionary advantage this might give us, I can't really say. But it does give a real boost to consumer capitalism.