I turn around to see one of my little Year 7s and his friend walking behind me. I forbear to point out that they're walking up the down stairs, and return the greeting. I then speed up to get into the staffroom as quickly as possible.
As I'm vanishing through the door, I hear:
"What's that teacher's last name?"
"That's Miss G________."
*pause* "Is she sound?"
I never found out, alas, whether or not I am a sound teacher. I'm not entirely sure I want to, either.