Many moderns would not even consider Friendship a form of love. Yes, we might go through life without ever having one great, good friend. It is possible. He obviously does not mean acquaintances. He means the least natural form, the least instinctive of loves.
Friendship has nothing to do with family, physical attraction or romantic love.
In fact, it is the one love we are never prepared for. It just happens. Usually the friend shares an interest. But shared interest is not enough. The friendship is bonded by mutual trust.