Why can nonpolar molecules pass through the nonpolar portion of a cell membrane?

Nonpolar molecules can pass through the nonpolar portion of a cell membrane because of the chemical principle that "like dissolves like".1

The cell membrane is composed of a lipid bilayer that features a hydrophobic, nonpolar interior made of fatty acid chains. Because nonpolar molecules are lipophilic (lipid-loving), they are able to dissolve directly into this nonpolar, fatty acid environment. This allows them to cross the membrane through a process known as simple diffusion, moving directly through the bilayer without the need for energy or transport proteins.5234

In contrast, the membrane acts as a barrier to many polar or charged molecules, which are typically repelled by the nonpolar interior. These substances require specific transport systems, such as channels or transporters, to move across the membrane.546