"Continuous effort, not strength or intelligence, is the key to unlocking our potential."
{ Liane Cordes }
Grasping one's true potential is in fact achieved through intelligence, perhaps strength, but not entirely through effort. One can only achieve so little through effort. This motivational key can die out sooner than intelligence can fade away (if it is even possible). I believe is is safe to say intelligence is the most essential "key" to unlock one's potential.