I think some people are.
I wonder if it can be affected by genes and such as my mum has meniere's disease which I inherited from her, early onset arthritis (ditto) and looks like I may have inflammatory bowel disease which I think my nan had.
It can also be environmental, I suffered badly from an eating disorder which royally screwed up a lot of my digestive system and weakened my kidneys.
It's strange as my brother is never ill (doesn't even need glasses like the rest of the family) , think he got all the good genes haha :)
It frustrates me I can't do a lot of the things I used to (used to be soo active, RAF cadets, riding, climbing, canoeing, dancing, always out and about) but there are ways of adapting.
Ok so I now struggle with rock climbing and riding and may not be doing another 36 mile canoe rally etc... but I've found other things I really enjoy like photography, visiting zoos etc...
I have a partner and it is hard though he's very good and his former partner had lupus which is far more serious than anything I have and they were together a long time.