Relationships require at least two participants, and each member has a role to play within that relationship. I’m not just talking about girl/boyfriend relationships here, I’m talking about all kinds of relationships from friendly to professional to loving. The nice blog, Water Cooler Wisdom has an article on how to ensure a long-lasting and enjoyable relationship.
The key point: be good and pull your weight.
Workplace friendships in particular can develop into some of the most meaningful relationships in your life, but you have to be willing to put in a little effort beyond just saying hello in the hall or eating lunch together in the cafeteria. If you decide it’s not worth it to you, that’s fine, but if it is, don’t let relationship laziness get the better of you.