Immune strength
Huh! People with strong immune systems probably get more colds and more cold symptoms. Jennifer Ackerman for The New York Times:
…susceptibility to cold symptoms is not a sign of a weakened immune system, but quite the opposite. And if you’re looking to quell those symptoms, strengthening your immune system may be counterproductive. It could aggravate the symptoms by amplifying the very inflammatory agents that cause them.
I can’t believe that never occurred to me before.