Almost a teenager

This evening Nathan and Nicholas were watching a Diego video.  Nicholas was trying to tell Nathan some fact that they had both just learned from the video.  Nathan says " I knoooowwww Nicholas, I'm almost a teenager!"

I said "No you aren't".  He said " What's a teenager?"  I told him he'll be a teenager when he turns 13.  He said "oh, I guess I'm not a teenager then." 

Nope and don't try to rush it.  Geez