[bamboozled]

This is an interesting phenomenon which I personally experience too.

If I have something really important going on, I basically don't get sick, when I finally kick my feet up, I just seem to get hammered with a bad cold or flu.

I also think it's interesting how my body seems to understand when I can't poop, like if I'm in a train or something without a toilet and just doesn't seem to bother until I tell it it's ok.