You are smart enough to understand that being smart might make it easier to understand big picture, and relations between cause and effect.
Being smarter than that makes no big difference unless you study, study and study. Even then, it tends to bring more stress than happiness.
You are not stupid, nor do you miss anything. Only thing wrong with you is assumed inferiority to people smarter than you. Smarter = quicker, but life is story where travelling is the key, not end of it.bold