Time Enough For Love

The characters talk about the problems of never aging, when trying to live amongst people who do age. Heinleins book described a person in a similar situation. Lazarus Long had to use makeup to make him look as if he was aging, and then disappear for a time and "sell" his property to a stranger - himself without the makeup - who arrives in town a few days later. He tried to ensure he never fell in love with anyone, but was unsuccessful.