Mandy and Collin

The other day, I was sitting on my bed desperately trying to do my school work and stay awake at the same time when Collin burst out laughing and walked in to tell me what was so funny. Apparently, Mandy had decided she wanted to play with a wooden truck of Collin's. Collin grabbed the opportunity.
"You want this truck?"
"Yes."
"Okay, say 3."
"3."
"Say 4."
"4."
"Say 75."
"75."
"Now say Gastrophyliosophylus." (Yes, he made it up.)
"4?"
I suppose for it to be truly funny you would have had to be there but I just had to post it just for the benfit of seeing those who tell me "You need a life" eat their words.