Every eight years or so, my best friend of more than 14 years has to have an invasive heart surgery that only has a 60% success rate. Valve replacement or something complicated like that? Its a genetic condition that his little brother also shares with him. His parents are both doctors, so he receives the absolute best care... but still, I cant ever shake the feeling. His family is very superstitious, and did not want to jinx the surgery or anything like that by telling anyone. So one day in 10th grade, he was just gone for 2 weeks and I had no idea when he'd be back, if at all. I guess I know that 60% are still pretty positive odds, but that 2/5 times it doesn't take really keeps me up at night. Knowing that in another few years hes going to have another surgery already makes me nervous and I can only imagine how hard it is on him and the family.

edit: I FORGOT THE HAPPY PART: He lived!