First, we need to categorize boys so that we fully understand them as parents. the categorization that follows is actually coming from our favourite pediatrician who developed it through decades of work with babies and small kids. By the way, pediatricians are the most important people for parents up until the boys reach adulthood. As one of my friends put it, she is ready to lose her husband, her work, but she sticks to her pediatrician.
So the categorization is simple, there are two types of boys. A boy can either be a "ball" boy or a "car" boy. The " ball" boys as the name suggests, love balls of any color and size. But it is not only about the ball. The ball also represents the love of moving around. A " ball" boy enjoys movement and loves to play games that involve physicality, running, skipping and you name it.
The " car " boy on the other hand is the opposite. He loves watching others move, especially cars but any mechinal objects of size for that matter. So these boys adore construction cranes and bin trucks equally.
I am lucky as I have direct experience of both types of boys. My first one was a typical "car" boy. He collected toy cars from an early age. We also spent endless minutes on street corners watching cars simply passing by. We looked at the bottom of parking cars to check for the exhaustion pipes. At that time I was convinced that my son, when he grows up, he will become a parking guard.