Need and Want have different definitions in my book.
You bf has a point about "need". We don't need anything except the air to breath, food and fluid to keep us going, and perhaps shelter over our heads (that old hierarchy of needs idea).
Want are things we can live without but can be very high priority in our lives. I want my husband/child/family to be happy. I want to have friends/lovers who are comfortable with who I am. When these wants go unfunfilled, it can be just as damaging to us physically and emotionally and a need not getting met, but the chances of us dying from it, not likely.
I think it is a good idea to know what you want out of a relationship and what your partner(s) want out of a relationship. It may not be necessary that a single partner can fulfill all of the needs (poly can be nice that way). Some wants may be deal breakers, if you want children and your partner does not ever want to have children for instance. But some can be worked around, especially in a poly relation where one partner may complement where another does not.
Life is about the journey and not the destination,
so what better way to know life
than to wander all the roads and paths set before you.