Did I win the lottery or is it a curse?

I certainly wouldn't rely on a teachers edition, but I wouldn't feel the least bit guilty about looking over it toward the end of my studying to make sure I got everything. Basically, as long as you're not using it to avoid having to really "learn" the material, then I don't feel like there's a problem. Also, there's really no reason to worry about whats "fair" to other students; let them worry about themselves. Personally, I don't even see whats so "unfair" about the whole situation, anyway. Correct me if I'm wrong, but if you had money to burn, isn't there a huge number of books and study guides available to help you learn the material? I really don't see a huge difference between looking over the teachers edition to check your work and buying additional study guides at a bookstore. Ultimately, its your choice, but I think you're making a bigger issue of this than it needs to be.

EDIT:
I agree with the first two replies: Do NOT let your classmates know you have a teacher's edition. While I still believe that its not a big issue for you to have the book, there is always that one student that feels bitter about his own failure and wants to take others down with him.

I had this happen in a pre-req class. It was a help but it sure didn't reduce my study time. Definitely don't tell a soul.