5 years EMS now and never did a preflight  

I worked with a pilot back in the 80's that never did a preflight, just jumped in started up and was gone. One Saturday morning I walked down to the helipad and as I walked by the aircraft I turned the tail rotor. The whole T/R gearbox moved, one of the gearbox mount bolts had sheared, so I removed what was left of the bolt and called the pilot to come down to show him something. As he walked up to me, I handed him what was left of the bolt and told him this is why we do preflights.