I definitely agree with Justin on sense of self. There is no real self. We think and act as a function of our past experiences and current real-time stimulus. We are constantly in a state of change, and present a different side of ourselves in different environments (with friends, acquaintances, strangers).
A life strategy of self-improvement (which is essentially just changing our 'self' to correspond to something we aspire to) appears to be highly correlated with happiness and even health. While the ideal situation seems to be to become content with what we currently have and who we are (to disassociate from a sense of self altogether), the human brain is very easily pleased -- and perhaps thats the problem, it's easy but a short term fix -- with incremental improvements and successes. So, if you're not willing to invest time in meditation and aren't willing to hone your abilities in self control, you should find parts of yourself that you want to change, enter a strict regimen of incremental improvement, and enjoy the thrills of the small successes.