3 guys, an engineer, an accountant, & a software developer, were in a car at the top of a hill. they drove down the hill, but when it came time to put the brakes on, the brakes failed. fortunately, the car eventually came to a stand-still without causing an accident. they got out of the car. the engineer started taking off the wheels to see why the brakes had failed. the accountant started working out what it would cost to finance the various options. when they had finished, they asked the software guy what he thought. he said, "why don't we just get back into the car, and see if it happens again?"