You can think that if you want...

Today we drove down to Children's Hospital to get some bike helmets for the little boys (only $8, and they get fitted!).  So I point out the Arch on the way, and Z remembers that we saw it when we went to a Cardinals game a several years ago.  This prompts us to this conversation: 

-Yeah, I remember going there.  The little boys were there too. 
-No they weren't, bud, they weren't born. 
-Yeah, they were there.  They have been there. 
-No, they haven't.  They were in my tummy the last time we were there...
-Actually, Mom, they HAVE been there. 
-No, Z, they have not.  I'm not quite sure what you're thinking of. 
-Well, Mom, I think you're wrong. 
-Ok, I'm not wrong though. 
-Well, Mom, you can think that if you want.

Might not be as funny to anyone else, but these are VERY common phrases that Nate and I use to end conversations when we know Z is wrong (ok, Z, you can think that if you want).  We have also had to teach him not to say, Mom, you're wrong, but instead to say, Well, I think you are wrong.  Cracked me up.  Glad to know he is listening to us, but funny to hear it thrown back at me.  :)