School Nurse Humor

Yesterday I received a call from my son's school. It was shortly after 10a, so I wondered what could have happened so quickly in the day. It was the school nurse who had my son in her office with a note from his 3rd grade teacher. She wanted to let me know that my son had ingested a go-gurt from last week's lunch and his tummy didn't feel well.
I was a bit confused.
How did my son get a go-gurt from last week's lunch?
Did I need to pick him up from school?
How sick was he?
The nurse informed me that she simply read the note from the teacher and gave my son a lecture on dairy products and refrigeration. Something I had apparently overlooked. She then went on to say that I didn't need to come get him, she just wanted to give me a heads up. So, I asked again, how did my son get a dairy product from last week's lunch when he had a perfectly good, fresh lunch packed for him this morning. She asked, "Would you like to speak to him?"

Saunders answered, "hello." I repeated my question to him. "Why did you eat a go-gurt from last week when you had a fresh snack/ lunch today...and how did you get it - where did it come from?" He began to explain to me how, on Friday, he wanted to save the go-gurt for after school, but forgot it, and by chance, left his lunchbox in the lunchbox bin in the classroom over the weekend, so when snack time arrived, he thought he would take the opportunity to devour last weeks snack first. I think I threw up a little in my mouth. I asked him, "why?"
He simply responded, "I don't know."
I have a boy.
We had a conversation on the difference between refrigerated items and food items which are stored in the cabinet when he got home.