Almost all living things grow as they get older. Think about a tree you might plant in your yard -- it starts as a seed, turns into a sapling, and eventually becomes a full-sized tree! Animals are like this too; a puppy you can hold in your hand can soon become a dog as big as you are!
People are the same: we start out much smaller and get bigger as we get older! Humans are built to grow, with bones that get bigger if we eat the right things and make sure to get enough sleep! - And don’t forget that “growing” doesn’t just have to refer to getting taller! As we get older, we also grow smarter and more knowledgeable about the world.
Growing allows us to take the time we need to experience the world and learn about the things we need to do to survive! Most things couldn’t stay small forever because it would be hard to get by being so tiny and not knowing about the world. The different types of growth that you go through are meant to prepare you for being an adult! Our growth makes it possible for us to do new things as we get older that we couldn’t do before, which includes everything from driving a car, to making important decisions, to taking care of your own family!