I'm having trouble deciding what martial art to take?

I'm a slow learner so it's hard to remember a buch of things at one which leads me to believe if I'm in an altercation I wont think of the right moves cause there's so many, I wanna take either systema, ju jitsu, hapkido, judo or muay thia, like I said I'm a REALLY slow learner but I wanna learn a practical martial art for a real life altercation, I'm a body builder if that means anything thanks