(Tasteless, but somehow very poignant too...)
A man went to his doctor's, and the doc said to him "I'm afraid I've got bad news for you - two lots of bad news, actually. The first one is, your test results all came back, and you have cancer. I'm afraid it's untreatable, you should set your affairs in order, you probably have about 6 months at the most."
The man shook his head, and said "Bloody hell. So what's the other bad news then?" The doc replied "Well, the tests also showed that you have early-onset Alzheimer's Disease."
The man said "Jesus. Oh well, at least I don't have cancer, eh?"