I saw a young man reading one of the Tim Berners-Lee quotes on my 'quotes about IT' display, and disagreeing with it out loud, to his friend, who argued back.
A girl who started the year full of angry incomprehension at A-level work came to my class, in her breaktime, and handed in a complete coursework project, a day early.
I saw a kid open a door for a teacher overburdened with a box of marking.
Two young women, who had been withdrawn by their parents from an event I organised that was designed to promote religious tolerance, told me that when they had kids of their own, they would make sure that they went to events like that.
You feel you're getting somewhere.