Do you have a need for rubber bands? I do. I sort of collect them. Big ones, small ones, fat ones, skinny ones - it doesn't matter - I like them all. Never want to be without them, you know.
One time years ago, I needed a rubber band and couldn't find one. I searched the entire house looking for one and becoming increasingly bummed-out when one couldn't be found. Later, a whole bag of rubber bands came into my possession and I was thrilled. With this many, I'd never run out again. It never occurred to me that someone could buy a bag of rubber bands. Nevertheless, it's against some inner principle of thriftiness to ever consider buying a bag of bands. It's just a waste of money on a silly little thing.
But now, I make sure never to let my stash get low. If you look at the floor when you're walking through the room, you'll often see one and you can grab it up before anyone else sees it. And you can shove one in your pocket from a newspaper or from some broccoli. There are ways to acquire them if your vigilant. I know you don't ever want to run out of rubber bands either.
But seriously, I'm over emphasizing this. I don't care about rubber bands that much, just ask my family. And what if I did! People have their quirks. I bet there's something you can't do without.