I haven't played with DU yet, but I have plans for at least one of my sims to complete at least two degrees. He is going to study Drama at Britechester and become a musical actor as a young adult, but later decide to change careers and probably study Language and Literature or Fine Art from home. It's great for storytelling and lots of people study more than one degree in real life, so why not? It could be for various reasons, such as wanting a career change or simply for their own/your enjoyment. You could also think of an additional degree being like a postgraduate degree.
