From the outside, meditation appears to be a thoroughly serious endeavor. You have to sit down, dutifully count your breaths and rein in your wandering mind, and practice this every day whether it’s fun or not. But that isn’t Chade-Meng Tan’s approach to mindfulness. The founding chair of the Search Inside Yourself Leadership Institute, which started as a mindfulness class at Google and now trains employees around the world, Tan lives by the motto that…