If you know what times you normally enter Deep/REM sleep, you know what times it's important to get to sleep by and to not be disturbed at those points in the n

If you know what times you normally enter Deep/REM sleep, you know what times it's important to get to sleep by and to not be disturbed at those points in the night. They certainly vary by person and environment, but night to night they are fairly stable. Also, a lot of people are in denial about their sleep issues, "I don't hear any snoring".