That was just one theory, amongst the many, many boring ones the other theory which tickled me was that he changed it when he started public speaking as a means to hold the interest of the watching crowd - apparently the "doesn't that look a little odd" factor is quite handy for public speakers. Who knew!
Similar theory about Churchill was that he had a metal pin in his cigars so the observing crowd would be drawn in by wondering when the ash was going to fall from it.
Probably all b*ll*cks, but the theory amuses me at least.
Hadn't heard that before about Hitler or Churchill.
I guess both could just as easily be the true reason/s. Cheers.