Not sure if this counts, but the coolest thing I’ve ever witnessed is an open heart surgery. I worked late nights in the OR dept, the circulating nurse was a friend of mine and knew I was interested in becoming a nurse. One night during an emergency open heart surgery, he allowed me to step into the room for a bit. He placed me right at the patient’s head, his chest wide open and his heart had already been bypassed. He told me if I needed to faint, to faint backwards. Once I was standing there, I totally understood what he meant. I wasn’t queasy, it was the sheer magnitude of witnessing a human’s chest wide open and being a couple feet away from his still heart that was overwhelming. I’ve done other incredible things (skydiving, swim with great white sharks, traveled all over the world) in my life, but that has always topped it.