So well does nature work and so truly that she can make up for us in eight hours' sleep what fuel we lose in sixteen hours of activity.
Only one-third of the time do we need to sleep, and we have the other two-thirds for work and play.

This regular sleep is a strong force in our aim to keep rested.

Therefore, the plain common sense of that is to find out how to go to sleep naturally, how to get all the rest out of sleep that nature would give us, and so to wake refreshed and ready for the day.
To go to sleep naturally we must learn how to drop all the tension of the day and literally _drop_ to sleep like a baby.

_Let go into sleep_--there is a host of meaning in that expression.

When we do that, nature can revive and refresh and renew us.