A cold passed through the plane from Sydney to San Francisco. It was curious to watch passenger after passenger around me succumb to it: I was maybe third or fourth of about five. It's such a long flight you can see how rapidly, relatively, a rhinovirus is able to propagate itself.
Needless to say a fifteen hour flight is a bit of a mind bender. But I feel a lot better than when I first did it last year. Perhaps one's body remembers and anticipates.