I think that if you are part of a group, call it society if that works for you, there are benefits that you get simply by being a part.
For example, in my current social arrangement, there is a road that I use, there is a community watch program, trash service (free) and other things that I get simply by being where I am. I feel obliged to return something back to the society in some way , call it an unspoken/unwritten contract.
I think that there are a complex set of dynamics that are woven through this topic that could keep me rambling on for days, but the upshot is, yes, you should feel an obligation back to someone or some group from which you have taken some benefit. Call it a contract.
If you opt to be apart from some group, and garner no benefit from that group, then there is nothing that you should feel obliged (or "contracted") to pay back.
One caveat to mention is that, very often, one derives benefit from a group whether or not they've asked for it. Even in the remotest areas I've ever been in, there were at least trails. Someone, more likely some group, created and maintained those trails.
For me, I feel compelled to take care of the effluent that someone elses's work created, and that I am now using.
Not sure if the foregoing makes any sense, but, yah, those are my thoughts for whatever they are worth.
