Knowing math is like knowing how to use a computer. People who haven't done it much assume it's much harder than it actually is. Calculus really intimidated me in high school, but thankfully I conquered that fear enough to go on to earn a math minor in college. Funny how something that initially seemed so foreign and unknowable showed itself to be more and more elementary with pratice. With hindsight, I can tell you don't have to be a genius to do well in a calculus course. The students who do well are generally the ones most determined to overcome whatever initial challenges they encounter until they fully get the basic concepts.