Again and again and again and again.
I hate it when strangers incessantly ring the doorbell when it's obvious that no one's home (or, in my case, when I don't want to answer it). My paranoia sets in; the rate of my heart beat reminds me of being tied down the train track and hearing the steam engine whistle its signal for departure--I have to run but I can't because I'm trapped and can only hung my head down and hide between the crevice of my curved body and the metal tracks. And wait, until help comes along.