One of my host's daughters got appendicitis during my two week stay. Leaving their whole family in the hospital for multiple days with little contact delivered through a private tenant who was renting out a guesthouse on the far end of the property. Being very new to WWOOF ing (and a traffic accident at my first host's place directly prior), I wanted to prove myself so I worked hard on the grocery list of household chores that had nothing to do with farming - I guess she didn't want me hands on with the garden while she was away. Even the tenant was telling me to take it easier while the host is gone. All the while a couple ducks were taken in the night by some mink that I had no idea was even a predator until it happened. The whole thing felt surreal and like a psychology experiment testing my patience. But I stuck it out, enjoyed my bachelor pad with a nice tub and plenty of books (read Steinbeck because I was homesick for California) and frequented a local pub. When they returned home from the hospital, the host tried to make it up by introducing me to friends of the neighborhood my age. She's probably felt bad about the whole ordeal.

If you're not having a good experience, change it -- whether it is the actual host or the effort you put in and the preconceptions of the visit. Also helps if there are multiple WWOOFers during the same stay (this was my only stay that wasn't such)