I see two ways to approach “need” and “fulfillment,” the political and the existential. Re the political: the feminist movement fought to gain full human status for women. The rationale for denying that status had been that femininity itself was a defect – only remedied by the guardianship of men.
Simone de Beauvoir counter-argued (in The Second Sex, 1949) that “femininity” was a social construct, a choice, a grammatical convention, hence something that could be transformed at will. Not an adequate view (philosophically it drew on Sartre’s implausibly extreme doctrine of freedom in Being and Nothingness, 1943), but a necessary tactic, and the American feminist movement took it over.
The tactic provided body armor during the single-woman years of my adult life. I would go to New Year’s Eve parties peopled by couples – only me solo – and be unfazed. I would go out for Thanksgiving dinner alone, to a restaurant crowded with families gorging on turkey & fixin’s, and think, the company I have (my own) is better than yours! Was it bravado? It was a tactic, but a necessary one, and it became second nature, as feminism meant it to be.
But there is an existential sense of need/fulfillment that has to do with the exercise of our full humanity. Our fractured selves want to be whole – the puzzle pieces to find their place in the full picture. The love of friends, who bear witness to our struggle and of a partner in life who shares it, help us to understand our lives — and to want to live.