My son used to put his pointing finger on his chin and say, "Hmmmm." like he was thinking. Not sure where he got it but it was really cute. My Dad would incourage my son to do it. Dad would say, "Hey Buddy let's think about it... hmmm." My son would happily oblige since he likes to perform. He must have had him do it thirty times at least. Well my son and I were at my house and my Dad called. I said, "Come here and talk to Pa sweetie." He looks at me puts his finger on his chin and says "tink bout it... no" Then he runs away giggling. I finally caught him and he jibber jabbered incoherent stuff to Pa for a while and then handed me the phone. But I thought that was classic. "Tink bout it... no" LOL Both of my kids are smart alleks like me!