Pine cones. Stock-market quotations. Sunflowers. Classical architecture. Reproduction of bees. Roman poetry. What do they have in common? In one way or another, these and many more creations of nature ...

We've all seen it happen: finding the motivation to actually make it to 6 a.m. boot-camp with a friend; nailing the last round of squats when you see those around you powering through; or pushing ...