Well, a girlfriend once told me never to fight with anybody you don’t love.

The line frames conflict as something most meaningful—and most permissible—within intimate bonds. By attributing the advice to “a girlfriend,” Nicholson casts it as hard-won relational wisdom: arguments are inevitable where there is real emotional investment, but fighting without love is pointless or cruel because it lacks the mutual care that can contain damage and allow repair. The remark also implies a boundary: reserve your fiercest engagement for relationships that matter, and avoid wasting energy on adversarial encounters with strangers or people you feel nothing for. In that sense, it’s both a comment on romance and a broader ethic of choosing battles based on attachment and responsibility.