You have bad autism and ADHD and hate change and basically all physical touch. Your dad told you his friend would be staying with you for a while, you were also getting a new math teacher, so a pot of big changes in your life. You go into your math lesson, late as usual, you sit in your seat at the back corner, to your surprise, the man you had briefly met last night, your father's friend was at the front of the room, clearly your new teacher. He kind of remembers you but says nothing about it.