I'm not sure the toothpaste thing is really about loss aversion so much as it's about minimizing effort. Throwing a tube away, opening the box of a new one, unscrewing the new cap, putting it down, and fiddling with the the aluminum or plastic cover on the new tube so you can take it off while your hand is wet is so much more effort than just squeezing the old one a bit more so you can get on with your night and go to sleep.