Why Is It Hard to Throw Away 'Good' Food?

I've been cooking for myself a lot more, and branching out to new foods and--gasp--using recipes.
About 20-30% of the time I don't like what I've cooked: it's either overcooked, undercooked, under-spiced, or just messed up. I eat it anyway. A couple of things happen as I do this: I feel pleased  morally superior that I've not wasted 'good' food, and I remind myself that eating more food (especially food I really like) as a consolation prize is no longer acceptable for me. That was true until The Bad Curry Incident.
I've made curry three times using this recipe as a base. The last time I made it, it seemed runny, so I decided to thicken it. I don't use flour (or any grains) these days, but I did have an alternate thickener, arrowroot powder. In my rush to improve the curry, however, I used cream of tartar (an acidic agent used in baking and increasing the volume of whipped egg whites) instead. Why? I don't know. Did I really think one white powder was as good as the next? (It is a good thing I do not have cocaine in the house: "But Your Honor, I thought it was arrowroot!")
Well, the cream of tartar didn't work. I then rummaged around, and found the arrowroot powder, which did.
So, I now had a bitter-tasting curry on my hands. What was I going to do with it? At first I kept tasting it--as if it would suddenly, miraculously get less bitter with each taste. That night I ate a serving for dinner, and put the rest in the fridge. It wasn't very good at all. I felt ripped off.

I bet Queen Vicky woulda ditched the curry.

(That apocrypal  story about Queen Victoria played in my mind as I chewed. The Queen was said to abhor sex. When asked how she was able to engage "in the act," she replied," I close my eyes, and think of England!")
Today I was going to make another curry (I have some beef I need to use), and mix it with the old curry and so salvage the failure. There was, after all, some expensive, free-range meat in that tartar-ed up curry, so I shouldn't waste it, should I?
I realized, though, that I was punishing myself for my mistake, and holding onto that failure, to boot. I threw it away a few minutes ago, with only a small amount of guilt.