Last summer, I noticed a shift: I was calmer and happier than I’d been in years. This was puzzling, since my life didn’t look particularly calm. I was planning a solo cross-country move, and my days were full of bubble wrap and goodbye dinners and Craigslist alerts. But as I packed up boxes in Boston, and then adjusted to life in San Francisco, I marveled at the little changes. Feeling content, ra...