Being a 'child of the 60s' and the 'Cycling Proficiency' scheme, as delivered by the fearsome and stern PC Bennett - a legend in Middleton policing - I was MADE to set off and stop on the left foot. I was 8 years old and he was an awful lot bigger, especially in the hat!
Ten years later when he trained me to deliver the same training we were still instructing 'left foot down'.
When I, briefly, rode time trials we were pushed off right foot leading.
When I took motorcycle training a little later it was 'left foot down' so the right foot covered the rear brake* so, for me, it is ingrained. I can't do it any other way...
*YES. I DO know that Beezers, Trumpets and other old shite came with the gear pedal on the wrongother side. They're so few in number as to be statistically irrelevant . . .