Why did Bill Gates treat their children as normal during their childhood?

Rory gate was not allowed to use mobile phones until he reached 13 years old. It was innovative and astonishing to him. Father had taught his children. All three of them were questioned with the same standard. Bill Gates is a successful entrepreneur who raised his children to be normal and was treated in that manner. Though he had plenty of different ways to use the phone, due to the rules that his family enforced, there was nothing he was permitted to do.