My father is insane

[Terra]

Yeah, lots of older people do stuff like that. It probably comes from being broke before you were born, worrying about money and crap like that. It comes from seeing people waste things (particularly kids who still live at home doing really stupid shit that cost their parents money) and just not having enough money in general to spread around.

Then later on in life when they are a bit more financially comfortable they hit mid life crisis and buy the things they have always wanted in their youth while still holding on to the same old habits of squandering that they had in the first place. They probably do some pretty extreme stuff (like the milk thing) now to justify the shit they spent on themselves.

Then again, he could just be one crazy old coot and your going to do the same thing too, later on in life.