Inter-library loan is not available everywhere and often costs money. Patrons might be able to recall checked-out books but they might still have to wait two weeks until they can get it. Or there might be a wait list for the title. Or it's non-circulating. Or... Or... Or....
Sometimes you just gotta buy it.
GAP insurance. You know it is a waste of money as the dealers try so hard to sell it you. The odds of you totaling a car in the first year of ownership is pretty low. After a couple of years you will owe less than it is worth so it won't help you anymore.