It can be passed on to your next generation.
People can usefully refer to it throughout their lives.
An accident or emergency. Moving from one doctor to another. In addition to providing a centralized record for its owner, it can be used to keep track of immunizations, social factors, various treatments etc. It also gives you the option to potentially generate revenue by selling limited advertising space in the booklet, thus offsetting your initial investment. It is made of a durable material which cannot be torn or damaged.