For some people the rubber hairbands are to be used to put one's hair up into a ponytail. For my Pumpkin, it's her favorite cat toy. We have a ritual every morning. She waits for me right outside the shower. When I'm finished I turn on the water faucet for a slow stream so she can take a drink. She likes that too. Then I go to the doorknob where I have about a half dozen hanging and I give her one to play with. She plays all morning with that until I leave for work and I put it away. The reason I don't leave her with it is because she likes to eat weird things like rubber bands and plastic grocery bags. She's never tried to eat the hair bands but you just never know when you have a strange little cat.
Back when I had three cats living with me I went out and bought a kitty condo. You've seen them, they are covered with carpet and have little "rooms" inside for them to go in and out of and are in a tubular shape. Well, that thing sat there untouched until I sold it at a garage sale a couple years later. But that said, if I was to empty a case of pop or a paper grocery bag (you remember those, I know you do), they'd play and go in and out for hours!
Cats are so entertaining!