I really enjoy binding! I machine the top and hand sew (the folded edge of the binding to) the back of the quilt. I suppose I'd be cranky too if I had done what you did. Chuck this up to your big oops! I bet you'll never do that again. I usually cut, iron, roll up my binding material (and store it in a baggy) when I'm finished cutting all my material before I even start sewing the top of the quilt.
However, recently I used left over backing material from when I rented the LA at a LQS. I felt strange coming home from quilting and NOT having my binding ready to go. Very little waste this way. I'll have to wait and see which is my preferred method for the next quilt.
I love hand sewing on the binding while watching tv. It's a relaxing way to finish a quilt. I'm kept warm at the same time. Something that will warm someone else's heart and body is keeping me warm at the very end of the project!