I don't think lefties have screwed up brains! I do believe in etymology completely however and left in Latin is "sinistra".
Sinister means evil, malevolent, ominous, with suspect intent!! So how could I ever be expected to trust these people completely? I've noticed when their golf ball is directly up against a tree or whatever in a way I could never play it they seem to get off Scott-free! I'm not sure what it is but fundamentally it seems they're up to something no good, I can tell you!