Relationships have a big transactional element. The strength of a relationship is typically directly related to the willingness of the two individuals involved to give more than take. It is something we all are aware of at some level (the degree is self awareness dependent).
The funny quirk here is that the moment you consciously think of a relationship as a transaction, you have sealed its fate. Perhaps it is because the thought of the word transaction has us focus on “what’s in it for me?”
The trick is to approach giving in relationships like lunch. You do it every day. It’s good for you and you don’t think about it.
(And, similarly, approach ‘taking’ like an unhealthy midnight raid of the fridge – I realize this analogy doesn’t apply if you are a university student…)