This evening I ended up contemplating fish. Specifically, fish swimming upstream. Have you ever had that kind of a day where everything is a slog? A fight? A grit-your-teeth-and-hang-on-to-your-sanity-by-your-fingertips-with-all-your-might sort of struggle? I was in the middle of yoga class, clearly having failed to empty my mind and let go of all those bothersome concerns…