Mutuality

All the books I've read, about characters of all sorts...philosophy and history or even fantasies playing out all the what if scenarios don't seem to do much good in offering practical perspective to questions in my own life.  Occasionally I come back to the same big one, "what is happiness and am I there?".  Moments like these I want to ask a reliable fortune teller about everything and forget about it the next day.  When does happiness become a selfish frivolous desire. When is it still a remaining matter of self preservation?  How would I explain this to my daughters in their own pursuit of the same?  I watch my parents sacrifice moments of potential joy for a greater sense of salvation later on.  That is, assuming two people can meet each other half way over time.  That is, the assumption that in time you would find that common ground.   Would the foundation be selfless sacrifice and love?  It takes two, when two is involved.