The Toilet Seat Dilemma

[Walking Void]

I have been ill on many occasions throughout my life - I have no idea what the cause was in the vast majority of those cases.

Standard symptoms? If they were, You can turn your attention to the common cold and influenza viruses.

Both are airborne during coughing/sneezing, and they have a fairly high lifespan on surfaces, with the cold living for approximately 2-3 times longer than the flu.

It is quite possible that a strain of dormant virus was in your midst but the only person not immune to it at that time was You. It is quite possible that it spontaneously mutated through imperfect cell division and thus was not identifiable by your antibodies.

Or maybe You just tend to be Bad Luck Brian. The possibilities are not endless but vast.