I'm not sure why this struck me, or why I even realized, but it seems like a milestone. A big one.
Like when they started consistently sleeping through the night, like when they could use their own fork and spoon, like when they switched from crying to just playfully calling out when they woke up from a nap...
Maybe that's it. Those are all developmental stages. This is a growth measurement. My boys are actually growing up.
What were the milestones for you? What was it that made you realize your kids were growing up?