Options are particularly difficult to understand. Put and call values are determined by the price of a stock, and yet you do not need to own the stock to buy a put or a call on that stock. In addition, if you buy a put or a call, you have the right to walk away from a contract to limit your losses. When we compute the price of an option, we use two models that are difficult to understand and have computations that are particularly challenging. Please share with others some of the challenges you encountered.