Resource Guarding?
I tend to get really excited about certain snacks/treats, but I either wind up forgetting they exist (despite putting them out in the open) or justifying that it’s not the right moment. This leads to things expiring, or in general getting to a point I’m no longer interested, and I hate the waste of it. Any suggestions how to combat this?

The best thing is not to buy additional things if you haven't run out of it. Plan your meals maximum for 3-4 days and buy only those things you need for the recipe. You will end up with a clean fridge, all the ingredients will be in the eyesight