eating the leftovers on your plate, he is keeping them for another meal. "I could make a mean stew out of this." I hate Dad's stews...
Dad loves to conserve things. From using the very last bit of ketchup from the bottle to saving every last penny, Dad knows how to make use of every last thing in your life. Some call it being thrifty, Dad calls it common sense.
This thriftiness is also economical and sentimental. His torn t-shirts may scream unfashionable to you, but to Dad they say "look at the money you've saved by not buying new clothes." And why is Dad saving all your old clothes? He really does miss you as a baby. (You'll thank him in college when you have the best themed party outfits).
That's why you can find your batteries in the freezer "because they last longer when stored in there," or get yelled at for touching the thermostat, you understand Dad is just looking for ways to make things more efficient. While mom sees beauty in all things, Dad sees opportunity in all things. Another man's garbage is another man's treasure? Wrong.
Another man's garbage is Dad's treasure.