I missed out on patterns at Uni, they were just starting to take off in a big way in the land of OO and so we wasted our time learning about formal specification languages and the like.
Anyway, I came across a great book that explains design patterns and WHY they are can be useful. I always found pattern books do a great (if dull) job of explaining the pattern, but struggle explaining just why you should use them. But this book - Head First Design Patterns, is LOADS better. It gives really simple readable examples of why you should use certain patterns, as well as why you should sometimes avoid using them... and its actually a decent read - which you can't say about many software development books :)
Check it out...