Bungee Jumping

I mean what possesses people to hurl themselves (occasionally pushed) from the top of a crane attached only by a piece of twine to confront the fast ascending concrete racing towards them from below ?

Is it the impending backache or the blood shoot eyes?

Never understood the need , having allways clung to dear life every time I have ever had to scale the heights.
Has there ever been any long term University survey carried out to determine the loss of life expectancy due to this type of operation and the wear & tear on one's heart....