I did not spend my university years wisely. In fact, you could say that I wasted them.
In most respects I'm not any better off after graduating. I took a program that I was able to complete without much trouble and also one that didn't have a clear career path afterwards. I took the easy route without thinking much about the future. I'm sure if I had taken it seriously and applied myself I could have made something of it. Grades just weren't important to me after that 50% mark. I figure I've learned more on my own in the last two years than I did from all my university years combined. No doubt it has something to do with the difference between wanting to learn and being forced to learn. However, that's no excuse.
You might think that I spent my time instead partying with friends and enjoying myself, but I can't say I did that either. An embarassing and telling fact is that I found myself with fewer friends after graduating from university. I lived at home with my family and didn't get to experience living on campus. Though, knowing how I was at the time I probably would have found a reason to dislike it terribly anyways.
Don't do what I did kids. My four years went by in a flash and I've nothing to show for it except being four years older. Even if my degree was worth something to someone, I wouldn't be able to convince myself of its worth. I cheated myself out of a great learning opportunity and an enjoyable university experience.
So my words of wisdom are to enjoy yourself and to try to do the best you possibly can while there. Prove to yourself what you can do.
On a depressing side note - I would have ignored this advice even if I had read it before starting university. Don't be like me.