... actually I blame the car manufacturers - French, Japanese, German - yes, mostly German!!!
The thing is, I am now old enough to look back and remember vehicles with built in indicators - they came as part of the package, like wheels and seats.
If you hav'nt cought up with me yet - just take a drive on any motorway. You will see two distinct types of vehicles - big flashy ones which gracefully drift from lane to lane - the driver has a mobile phone in one hand and a Costa Coffee cup in the other, and little flashy ones which defy the laws of motion by shifting horizontally between lanes appearing on your front bumper then disappearing before you can get to your flasher - the driver sports a baseball cap and a long middle finger where his apology should be...
I can well understand there is a very fine line between a GOG (graceful old gentleman) and a BOF (boring old f***) - and knowing what the car in front or behind is thinking of doing next is not being nosey - it's being safe!!!!