Acharya Prashant explains that marriage, while a ubiquitous social institution, must be defined by the individuals involved rather than following a standard replica of millions of others. He emphasizes that closeness should not imply clinging or constant physical proximity. Instead, successful relationships, whether in marriage, friendship, or business, require well-defined boundaries and protocols. He argues that the romantic notion of two people dissolving into each other is a recipe for conflict because human beings are inherently limited. Respecting these limitations through 'good fences' allows for a healthier connection where both partners are free physically and psychologically.