What does it mean that environmental triggers are the most reliable?

Physical cues in your environment trigger more reliably than mental intentions.

Example: You decide to drink more water. You rely on remembering to do it — and by 3pm you've had one glass. Now place a full water bottle on your desk before you sit down each morning. You don't need to remember. The bottle is there. You drink. Anne Thorndike's 2012 cafeteria study at Massachusetts General Hospital found that simply placing water bottles in baskets near food stations — making water visible where people already stood — increased water sales by 25.8%. Nobody was told to drink more water. The environment said it for them.

Try this: Choose one behavior you've been trying to do more consistently — stretching, journaling, reading, taking vitamins. Identify the physical location where that behavior should happen. Now place one visible, tangible object in that location that makes the behavior obvious: a yoga mat unrolled by your bed, a journal open on your desk, a book on your pillow, a vitamin bottle next to your coffee mug. Do not rely on remembering. Let the object do the remembering for you. Track for seven days whether the environmental cue outperforms your previous approach.