I thought I had been so clever creating a colour-coding system for marking mock GCSE exam papers for five classes.

Red, green or amber based on achievement was a visual treat to begin with - greens straight down the register. Then the ambers started to creep in and finally the reds.

I’m not ashamed to admit it, I actually cried after marking one set of papers. My visual learning technique had emotionally destroyed me and I was beginning to see those red names as symbolic bloodshed, most likely a hint of what my head of department was going to do to me.

I went back to my PGCE files, sifting through my assignments and research essays trying to find out where I had gone wrong. Despite my emotionally fragile state, I still had 60 papers to go. Wearily, I went on.

Some were good, some were bad; some were amazing, some were downright laughable. I know it’s a cliche, but you can mark paper after paper and sometimes wonder if you were actually there teaching the lesson or if somehow the words that went through your head came out in Swahili. Then there’s that one pupil who totally gets it, nails the answer, and makes you realise that it really is all worth it.

This is why I teach, not to get 100 per cent pass rate, not to get 150 A*s, but if there’s just one pupil per class that learns something from you, one pupil who you can help on to the next stage of their education, one pupil that surprises all the others, that’s what makes all that red pen worthwhile. But I shall think twice about using that colour-coded marking system again.

Catherine Reynolds teaches RE at Saddleworth School in Oldham, Manchester. Email your NQT experiences to features@tes.co.uk.