Probably was that way before we got married and had a kid. And before our dog started getting older and we needed to watch what she eats.

Now the notion of "cook fresh every day" is a thing (rather than reheats), we try to do keep leftovers but eventually we run out of space for them.

absolutely. Cooking smaller meals for the family to ensure it's all eaten or having no-cook alternatives for afterwards (hello graham crackers!) if you're still hungry. Normally I try my best to portion for who's going to eat. If I'm cooking for myself, its usually a one-pan meal.