Happiness is spiritual, born of truth and love.
It is unselfish; therefore it cannot exist alone,
but requires all mankind to share it.

- Mary Baker Eddy


Today, try to feel the 'love' you have for yourself and others. If you love yourself more, then it is selfish. But, if you love others more, that's not a sacrifice..... just a reflection of unhappiness.
In my opinion, you need to balance the love you have for yourself and to others, then you'll truly be happy.
Sad to say, not every man can share their happiness. Man posseses this great feeling for others ...... not love but jealousy!