That utterly winds me up. The fact your dressed like vegetation and sat low amoungst stinging nettles seems to go right over their head as they stomp up to the waters edge and shout “THERES ONE!” as the fish bow wave out of the swim.
One of the worst ever was an old boy who was the bailiff for Verulam Club on the Lea at Wheathampstead in Herts. He wore a light colour mac and would walk up this VERY shallow river in full view and demand your membership card EVERY SINGLE BLOOMING TIME EVEN THOUGH IT WAS APPARENT HE RECOGNISED YOU FROM UMPTEEN PREVIOUS VISITS.