a) I can't believe somebody would post this on here... are you a paranoid American?
b) I can't believe somebody would have nothing better to do than to get out of bed at 0657 in the morning to look at a plane flying over their house when they live 4 miles away from an airport (I know where Maidenbower is before you ask. Maybe you work in the day, but planes do fly over there occasionally).
and
3) I can't believe you've ever heard an imminent collision!
(I just realised there isn't a 'hilarious laughter' emoticon!)