I just had this conversation with Parker after he brought me a toy raccoon that he found that another little boy had forgotten (keep in mind that he's not yet even 2):
"Mama, 'dis, pitty."
"Oh, is that Jack's raccoon?"
"Pitty hand."
"Yeah, I think Jack must have left that here."
"I don't think so, mama. Parker hold it."
"You want to play with it? You can play with it now, but we need to take it to Jack later."
" I don't think so."
"Yes, we need to take it back to Jack, or he will be sad."
"No sad, Jack."
"Right, so we need to take him back his toy."
"I don't think so. Parker take it."
"No, you play with it now and we'll take it back to Jack later."
"I don't think so, Mama. "

I don't know where that "I don't think so" came from, but he says it all the time now. He amazes me with his ability to express what he's really thinking. And he's already exhibiting selfishness. :P