Smart or ????

I was busy folding laundry in my bedroom, halfway watching "Star Trek: The Original Series" when my four year-old son came running in. He had been watching "Dora the Explorer" in the living room while eating his lunch.

He ran in and told me "Grandpa's knocking on the door!!"

So I went to the front door and opened it.

No one there.

My four year-old son then doubled up laughing his little tiny butt off. He all but rolled around on the floor laughing his butt off.

I said "Did you just TRICK me?"

In between baby gufaws, he said he did indeed trick me.

Is a four year-old really smart enough to pull this kind of trick off? And is he really smart enough to understand the humor of seeing his mentally sound mother staring out a door at nothing but snow when she expected to see her father in-law there? Or did somebody TEACH my little boy to do this? Who was it? Let's just see how I get YOU back .....

In the meantime I'll tell this story to everyone I know because it's just about the funniest thing that's ever happened to me personally - and I'll have to watch out for my four year-old who is apparently becoming smarter than me .....