There are a lot of things to learn and remember in diving - breathing, remaining calm, underwater sign language, how to clear a mask filled with water, and more. It was challenging (for me) to say the least. The instructor kept telling me to stay calm and relax. And in the end after many failed attempts, he told me that I am too tense and don't know how to relax. Too tense. Don't know how to relax. Hmm...that sounds familiar.