What has been the most terrifying moment of your life thus far?

There have been few moments where I feared for my own life. One time I went on to go swimming to middle of a beach without knowing how to swim. I think this might be one of the stupidest moments of my life where I made the worst decision even after having enough information. Another such moment is when I went far car driving and nearly left the car hanging. This was not poor judgement on my side but still I feared for my own life. There are also many mini heart attacks where I made not best decision while driving to and from office.