I've been adding up how many teachers our languages department has turned out since I joined the school in 1978. It hasn't been many - six - and two of them are my daughters.
But when Ruth came into my class it was obvious she was a natural linguist.
You would write up something about grammar on the board and, while everyone else switched off, she would put up her hand with some insightful question.
She was so keen, she rekindled the buzz I used to get when I first went into teaching.
I taught her French from S1 and then she took up German in S3, and every day you could see the thirst and excitement for languages bursting forth.
Her family wasn't particularly prosperous and I think she was the first one to show any aptitude for, or desire to go to, university.
Then, in S4, her mother decided to emigrate to New Zealand. Her father wasn't on the scene and it was expected that Ruth would go too. Indeed, she was all ready to, and showed me the brochure for her school. But she could study only Japanese or Maori there, although they did suggest she continue German and French by distance learning.
Ruth knew what she wanted, and she decided to let her mother and two siblings move while she stayed in Scotland. She lived with a relative in Glasgow and enrolled at a school where she could continue French. She had to study German through distance learning, doing it all on her own, but she did it.
She went to Glasgow University to read languages and is now studying law at Lyon University in France.
I've only ever received two thank-you letters from former pupils, and that makes it less likely that you'd forget them. Ruth is one of them, but even without her letter I will never forget her love of languages or how it made me feel, finding a pupil who was so enthusiastic about my subject.
John Mackay is deputy head at Dingwall Academy in Ross-shire. He was talking to Su Clark. Do you have special memories of unforgettable pupils? Write to Sarah Bayliss at the address on page 3 or email sarah.bayliss @tes.co.uk