All people are not the same, and we would expect some people to start practicing courtesy and gratitude earlier than others. The most efficient way to be is probably to have an ability to learn gratitude quickly, but to suppress the actual learning of gratitude until the moment when ingratitude stops being beneficial. We might expect socially talented but ungrateful teenagers to learn gratitude double-quick soon after they storm out of their parents’ cozy semi-detached house, and get a room in a shared flat in a dodgy part of town. Interestingly enough, it seems that this is precisely what happens, but with one refinement: whereas these young adults become skilled at being grateful to most of the people they meet, they retain an ingratitude towards their parents. When dealing with someone who loves one unconditionally, it pays to exploit this and to remain demanding. Most co-operation, most love, is conditional upon reasonable behavior in return.