No one told me, my friends didn't tell me

For the past two days Sammy has had a scab on his face, a sign of brotherly love from Carlos. Tonight as he was getting in the tub, I noticed that it was red. I asked him if he scratched himself, he said "no, Carlos did remember?" Then I told him it was red and it was not like that before. He then tells me that there was something stuck on his face so he pulled it off. I told him that he pulled off the scab, which then lead me to explain that the scab helps heal his face, and then I had to define heal. At the end of all the explanations, and definitions he told me "no one told me, my friends didn't tell me. I didn't know."
As far as I can remember this is the first time Sammy's friends didn't know something...they usually know everything. His friends are taking very realistic personas.