The plasma membrane or cell membrane is made of the lipid bilayer and the proteins are embedded in the this layer. Carbohydrates are also exposed to the cell surface in association with proteins and lipids.
The interior of the cell membrane is hydrophobic due to the arrangement of the lipid bilayer. The hydrophobic part of the lipid membrane are associated with each other that makes the interior of the cell membrane hydrophobic and small molecules easily diffuse through the membrane.
Explanation: your body needs sleep to restore the days information that you learnt and to 're -new' your brain and hormones etc. What you said is correct