Just wait until a pupil says "You taught my Gran".
Then you feel really old.
The school forwarded an email to me the other week
It was from an ex pupil who had been browsing the school website and saw that I was still teching there.
She talked of how she was in my first O level computer studies class some years ago.
She has been teaching IT now for nearly 30 years.
I'm not sure whether she was writing to say thank you or was making a complaint.
Still, it's really rewarding to know that you are remembered and have influenced a young person's life.