I was once working on a dataset provided by some Spanish colleagues. It had been created in a totally different system from ours, and I was converting it for use in our systems - theirs was Microstation; ours was ArcGIS for those who know their GIS software! And as anyone familiar with the systems will know, the differences in representation between the two are enormous. Anyway, I'd been working on it for a while when I discovered that one class of features had been duplicated in a manner that meant I was going to have to manually select and delete several hundred features. At this point, I boiled over and yelled "Bloody Spaniards!" Unfortunately, at just this point, our Spanish colleague who was visiting passed by our work area... Fortunately, I think he had a sense of humour and ignored my outburst! We collaborated many times over the years after that and got on quite well, but I learnt that day to keep my mouth shut!