When motivated students are allowed to progress at their own pace, they enjoy mathematics. Many are capable of so much more than what a standard curriculum provides. How many students could take calculus in the first year of high school if they were not kept at the same pace as their peers? At the other end of the spectrum, I have taught quadratic equations to students who struggle with basic mathematics because they need to pass a state test of first-year algebra. Shouldn't they be given the opportunity to grow in areas of mathematics that are more appropriate for them?