Go to bed only when sleepy, not just tired

Learn to distinguish genuine sleepiness from tiredness and wait for the former before going to bed.

Why it works

Tiredness is a general fatigue state; sleepiness is a specific neurological drive to sleep, signaled by heavy eyelids, yawning, and difficulty keeping eyes open. Going to bed tired but not sleepy guarantees early wakefulness, increases sleep onset anxiety, and reinforces the bed–arousal link. Waiting for genuine sleepiness, even if it means a late bedtime, produces faster sleep onset and a stronger association.

How to do it

1. Learn the felt sense of sleepiness — heavy eyelids, nodding, slowed thinking — and distinguish it from tiredness or "should be sleepy by now."
2. If your target bedtime arrives and you are not sleepy, delay by 30 minutes rather than lying awake.
3. Use the time to do something calm in dim light until sleepiness arrives.

Evidence

Waiting for sleepiness before going to bed is a standard stimulus control instruction grounded in the mechanism that sleep onset depends on sufficient adenosine load plus circadian alignment — going to bed without both is likely to produce wakefulness. (clinical)

This conflicts with a fixed bedtime; the general guidance is to use the sleepiness cue for timing and the fixed wake time to anchor the clock.

Common mistake

Going to bed at 10pm because "that’s when healthy people sleep" while being alertly awake, then cataloguing every minute of insomnia with rising anxiety.