I think one of the most stress-free things to do is watching floating flowers. Really, if you allow yourself to be completely focused for a moment on the flowers, observe its colors, its shapes, its fragrance, a serenity will start to come over you. My belief is that the serenes is part of Mother Nature's magic at work. Beauty brings enormous amounts of pleasure into our lives, and it is part of the human experience.
The irony of the rose in particular is the symbolism of both beauty and pain. How can something so exquisite cause so much pain at the same time? Nature requires balance so you cannot have pleasure without its opposite, pain. It's the torment and the ecstasy, the prick and the glow, the promise and the disappointment. In the acceptance of both as part of the life dynamic, we grow and evolve.