Why are lovers quicker to forgive their partners for infidelity than for leaving dirty dishes in the sink? Why will sighted people pay more to avoid going blind than blind people will pay to regain their sight? Why do dining companions insist on ordering different meals instead of getting what they really want? Why do patients remember long medical procedures as being less painful than short ones? Why do home sellers demand prices they wouldn’t dream of paying if they were home buyers? Why are shoppers happier when they can’t get refunds? Why do pigeons seem to have such excellent aim; why can’t we remember one song while listening to another; and why does the line at the grocery store always slow down the moment we join it?