I know what you mean. When I got my two baby girls, the woman helping me showed me this giant bag of Timothy hay. I thought, 'no way!' That bag is too much and would last forever. I live in in Mobile, Alabama, and with all the humidity here - I thought that it would go bad and get moldy just sitting around. I finally found a small bag. But after watching Patches and Peanut go through it, I soon realized that it was not going to last very long at all!
I've since went back and grabbed the large bag. I now keep it in a 13-gallon trash can (which barely holds it).