Obligations

So what are obligations really?  Who makes them up? Why are my obligations different than other peoples?  Obligations are so weird to me.  In my best estimation they are self imposed activities that must be done whether we really want to or not because in our mind are either morally or socially expected too.  They are self made, because each individual holds different moral and social ideals to some extent.  For this reason everyone has a different sense of obligation.  To me this is kinda interesting because if you find someone that feels similar obligations to you, then you morally and socially align.  My wife and I have dissonant obligations.  She rarely feels obligation towards the same things as me and I with thing she feels obligations towards.  Initially I didn't understand because I thought obligations were universal but they are not.  They are self defined.  Her self is drastically different than myself.  Therefore her obligations will be drastically different than mine.