Back in October, a friend was feeling theatrically hot-tempered as we sat down for lunch. She fidgeted in her chair and gesticulated wildly as she recalled a comedy of errors. She kept missing her train, forgetting her keys, arguing with her boyfriend, smashing her phone, and her porridge was never *just* right. “I know why though,” she confessed assuredly as she pushed aside her predictably stale sandwich, “It’s Mercury, it’s in retrograde.”