Can you use that in a sentence please?

Caelleb and I made cookies for him to take to school last Tuesday so his class could join him in celebrating his adoption day. When I had asked him if he wanted to tell his class about his adoption day he replied, "YES. I love being adopted." :)

We put the cookies into the oven and I headed into the living room. Caelleb didn't follow. When I looked back into the kitchen this is what I saw...

Me: You are impatient.
C: What's dat mean?
Me: It means you CAN'T WAIT ANY LONGER for those cookies to be done.
C: Yep. I'm dat.