It is true that you cannot always get what you want, but if you let people dictate what course or career you would want to choose, it would only mean disaster for you in the end. Make sure that you take control of this as early as choosing your major in college. The very first thing that you need to consider is to know which ones would interest you the most. It would be very difficult later in your professional life if you take something that you really did not want to take because you will simply end up being frustrated with the things that you are doing. As you ponder on it, also check the practicality of what you want to get.
At this day and age, whether you like it or not, money definitely matters. You choose a course because you want to be a success in the career that leads to it. Do not take a course if you know there will not be any money in there in the future. If it interests you, get the course where you know all companies would need to have.
The worst mistake that you can ever make is to get into the popular course during your freshmen years, only to find out that the competition will be fierce after graduation.