When the mind is coloured by a dualistic perspective, every experience – even moments of joy and happiness – is bounded by some sense of limitation. There is always a but lurking in the background. One kind of but is the but of difference: “Oh my birthday cake was wonderful but I would have liked chocolate cake instead of carrot cake”. Then there is the but of “better”: “I love my new house, but my friend John’s place is bigger and has much better light”. And finally there is the but of fear: “I can’t stand my job, but in this market how will I ever find another one”…I’ve begun to recognize..that feelings of limitation, anxiety fear and so on are just so much neuronal gossip. They are in essence, habits. And habits can be unlearned.
Yongey Mingpur Rinpoche, The Joy of Living
Mindfulbalance 
Have you noticed we are rarely satisfied with what we have? We always wants something bigger, nicer, better, richer, etc. We are almost never content with what we already have. But do be satisfied with what we have would be real happiness.