When should he grow up?

Hey height comes when it comes, and even if he was short forever, than if he adapts it will become his strength. With regards to acting like a younger kid, don't even worry. People grow at different rates, and furthermore, those that are different are those that see things differently, do things differently, and end up changing the world. I still hold many child like characteristics and I am 23, and they have repeatedly shown to have helped me in multiple ways. Someday in the future your brother may grow into enjoying other more older interests but until then and forever after I will give the same insights I came to realize in the middle of high school, "screw everyone else, you only get one life and this is it, so do what you want and what makes you happy, and do not worry about if you will look cool, just be who you are because that's the coolest you can be. Oh and what I found after I realized this was that when I acted the way I wanted, when I was free and natural, that was when I actually became cool, now that may not work for everyone, since some people's natural state may not be seen as cool by society, but what is universally seen as cool, is being confident in who you are, and not worrying about what others think.

I know this post is old, but I had already started and figured I would finish, hope your day is awesome.