I think that people get de-sensitised to something which they do regularly.
During a mountain-flying checkout (VFR), I was shocked at how few emergency landing possibilities there were. I asked my instructor where he'd put the aircraft if the engine quit. He thought about it for a minute, and then said: "Hmm, not many options are there? I guess I'd probably try to get close enough to the road that someone might see me crash and try to help me." This instructor had spent enough hours flying SEPs over mountains, without having had an engine failure, to not consider it a big enough risk to worry about any more. The same way that many of us don't worry about crossing the Channel, I suppose.
FFF
--------------