As a student, you have several subjects to study over the course of a day, with usually the same amount of time. As a worker, most of the time you don’t get to do enough of an aspect of the job that you enjoy doing but you get more than enough of what you don’t like to do! And they’re never for a set amount of time. Murphy’s Law would dictate that the bit you enjoy working will be too little or something problematic will crop out to make you enjoy the process less.