Dean's new favorite word is "cool".
I do say it often when he repeats words over and over. He'll say something like, "Doggie. Doggie. Doggie." and I'll say, "Yep. That doggie's pretty cool."
He picked up on it. It started out that Daddy and his shoes were cool. Now almost everything he likes is "cool". It totally cracks me up.
On a totally unrelated note, Dean head butted me so hard (not maliciously, though he sometimes does it when he's mad) today that it made me cry. Not just tears in my eye, but full out cry for a couple minutes. He hit me right on my ear and it pushed my ear into my glasses arm that pushed into my head. I still have a welt and bruise on my head because of it. Ouch. Not cool.