Rewards

When I do something for my mom-in-law, I usually get some form of fish in return - oftentimes raw with buggy eyes and scales that need to be removed or some sea creature with parts that dangle over the side of the plate. When I work for my uncle, I get cash and a giant watermelon. When I share produce with the young neighbor, I get beer. Honestly, why do I do anything for my mother-in-law?