So, don't give your two year old a banana to eat, and allow him to roam the house with it. Because said banana will disappear, and when you ask him where he put it, he will just run away and say, "Bye Mama, see you later!". And then you will find the banana days later. Except you won't know that it's the banana. You will think it's cat poop or something, because it is so disgusting.
And when did he learn to say, "see you later"?