Describe a course that impressed you a lot

I'd like to talk about a first-aid course I took last summer in Nha Trang, which turned out to be the most useful sixteen hours of education I've ever had. It was run over two weekends by a local volunteer group at a community hall near the beach, and it cost only two hundred thousand dong, mostly to cover the bandages. I signed up because my company wanted one trained person on each floor, and frankly nobody else volunteered. The trainer was a retired nurse called Mrs Thu, and she didn't bother with slides. Within ten minutes we were kneeling on the floor practising chest compressions on plastic dummies, thirty pushes and then two breaths, over and over until our arms ached. We also learned what to do about burns, choking, snake bites and, since this is a seaside town, drowning. What impressed me most was how much of what I thought I knew was wrong. I'd grown up believing you should put toothpaste on a burn and tip your head back during a nosebleed, and Mrs Thu demolished both ideas in about a minute. She kept saying, 'Doing the wrong thing fast is worse than doing nothing,' and that sentence has stuck with me. Three months later a man at the next table in a seafood restaurant started choking on a piece of squid, and I actually knew what to do. My hands were shaking, but it worked. He bought our table a round of drinks, which I consider a fair return on two hundred thousand dong.