I've recently been worried about getting a terrible illness such as cancer or dementia. It doesn't help that I was right about my marriage and having a son which I somehow always new. 
One thing always troubled me and that was I felt that because I'm not really ever I'll as such, that it would be karma for me to get one big terrible final illness. 
I've thought of using the knowledge to live life to the full ( if that includes drinking yourself to death), and going out on my own terms if I got the bad news. Other wise I'll just saunter through my days perhaps not realising that my brain is deteriorating until I find my self in my dressing gown writing on the Walls in my own shit.