Last year I went to the hospital with a suspected broken foot. They xrayed it and told me it was just a sprain, but that "interestingly" I had an extra bone in my foot. I walked as much as I could for two weeks, went back for a second appointment and was told it wasn't a sprain (or an extra bone) and was in fact broken in three places.

It's good to know they accidentally gave me good medical advice.