Turning 10

What happens when your baby(the oldest) turns 10. We are driving to the store and Brad started to bemoan our son's upcoming birthday.
Brad-"Erik is turning 10."
Me-"Yeah."
Brad-"Are you sure Erik is turning 10?"
Me-"Yeah."
Brad-"I remember him being born."
Me- "Yeah."
Brad-"Vividly! It seems like yesterday!"
Me-"Yeah."
Brad-"Are you positive Erik is turning 10?"
Me-"Yeah."
Brad-"Do you know what this means?"
Me-"What?"
Brad-"We are getting old!"