I failed some courses in my first year of university solely because of the attendance policy. Miss more than three days of class? You don't receive any credit for the class. The best part is I have a health condition that made missing that much class pretty much inevitable.
It depends on the resolution you'll be running things at, but I don't think I've ever heard of anyone needing 4 GB of GPU memory yet. Maybe if you are running at very high resolutions with very high fidelity textures. Also, I don't think you can fairly make a direct comparison to PC GPU memory and that of what consoles will have. They aren't designed in the same manner.