A non-feeder. No matter your desperate attempts to understand, it just won't eat. The longer it goes on, the more stressed you get. It's natural, especially if you have pets that eat daily, to think that if a pet eats - it's happy! So when it doesn't, you worry.
A hissy, stroppy snake is something that you can get over. It either tames down, or you alter yourself to fit the snake (don't handle it as often as you would like, but it keeps the snake happy).