I’m not sure [my story] is very interesting but I use it anecdotally every now and then in my current job. It happened when I was 10 (I’m female). English is my mother tongue and was the language of instruction too.
I went to a girls’ private junior school and everyone in my class was about to take the entrance exam to the senior school. It was the day before the exam (or that is how I remember it anyway, perhaps it was a few days before) and our teacher decided to show us how to do long division as she thought it might come up in the exam. I remember getting the impression that she was rushing (as the exam was so close) and she showed us an example on the board, then asked us to try several more examples ourselves. I did not follow at all and although I liked mathematics and had done well in it at school, I panicked, thinking that I would fail the exam. I didn’t ask for clarification as I sensed the time pressure – I had a feeling that I would be regarded as a nuisance. There were no long division questions on the paper and I did pass, but to this day, I have an irrational fear of long division. I have never spent time trying to understand it – I just never use it. I went on to take A level maths and have a degree specialising in Chemistry. I was a primary teacher before taking on my current role at NRICH (and now have a masters in maths education) and the lesson I described helped me realise that good maths teaching is not about instructing pupils to follow procedures without any understanding. I still cannot grasp why our teacher thought it would be a good idea to bombard us with this new algorithm at such a late stage. Well, I can understand in the sense that it was all about the test. I am not sure that this is helpful but please do get back to me if you would like further details.