Oxidation

Out of the blue, E turned to me.

E " Mummy. What is oxidation?"
Me " Er.... let me think " (i was scratching my head for a simplified explanation)

E " I know, when your apple turns yellow and brown, that is oxidation and you cant eat the apple anymore. You have to throw it away. It has turned bad"

Me " Oh! That is absolutely right. You do know what oxidation means eh! Smart boy!"

I thought to myself, I didnt know what oxidation is till I was about 10 I guess. Now, this little boy is not even 4 and he has been taught already. :)