I've just remembered the triviality. Yesterday, there i was at the traffic lights in the left of two lanes. As the lights turned green the car in the lane on my right shot off, indicated and moved in left well ahead of me. That was perfectly acceptable. However as i looked in my right hand mirror i saw one of those 'Chelsea tractor' police 4x4s trying to cut in front of me without signalling just before the road turned into one lane. I thought it bad mannered that Mr plod thought I wasn't worthy of a flick of a switch indicator light being activated so i didn't let him overtake me. 🧐