Think about the last thirty minutes before you fall asleep — the most repeated, least examined half hour of your entire life. But do the math: that half hour runs every single night, roughly ten thousand times a decade. For nine of those days, participants read a section of a novel in the evening — then got scanned the next morning to see what the night’s reading had left behind. That’s what the bedtime reader’s brain does for its last half hour, every night. Ten thousand nights is where “fundamentally different” comes fromHere’s the thing to be clear-eyed about: no single evening of either habit does much of anything.