Why should I monitor my sleep if I already know how I feel?

People often rely on vague impressions of how well they slept, but those impressions may not reflect sleep duration, interruptions, consistency or longer-term trends. Monitoring can reveal recurring patterns connected to stress, alcohol, exercise and irregular schedules while also making gradual changes easier to notice. It does not diagnose sleep or health conditions, but it can replace guesswork with useful information and support better conversations with healthcare providers.