From an essay, “The Search for Security”, by Bhikkhu Bodhi:
It may be a truism of psychology that the desire for happiness is the most fundamental human drive, but it is important to note that this desire generally operates within the bounds set by another drive just as deep and pervasive. This other drive is the need for security. However insistent the raw itch for pleasure and gain may be, it is usually held in check by a cautious concern for our personal safety.
Ordinarily, our benighted attempts to achieve security are governed by a myopic but imperious self-interest oriented around the standpoint of self. We assume that we possess a solid core of individual being, an inherently existent ego, and thus our varied plans and projects take shape as so many maneuvers to ward off threats to the self and promote its dominance in the overall scheme of things. The Buddha turns this whole point of view on its head by pointing out that anxiety is the dark twin of ego. He declares that all attempts to secure the interests of the ego necessarily arise out of clinging, and that the very act of clinging paves the way for our downfall when the object to which we hold perishes, as it must by its very nature.
The Buddha maintains that the way to true security lies precisely in the abolition of clinging.
The essential counsel that the Buddha gives us to secure our self-protection is to shun all evil, to practice the good, and to purify our minds. By the pursuit of non-violence, honesty, righteousness and truth we weave around ourselves an impenetrable net of virtue that ensures our well being even in the midst of violence and commotion.
(full essay here: http://www.accesstoinsight.org/lib/authors/bodhi/bps-essay_15.html)
Notice that the Buddha never said “There is no self”, or “The self does not exist”. Instead he maintained that building our universe around this individual self would lead to suffering. True security has to be based on something larger than one person’s idea of herself. Actions, relationships, all the ways in which we are connected with other beings in the world – these are the platform of our (shared) security. If we take refuge in the integrity of our words and actions, a perceived slight here or there won’t have the power to harm us.
It’s important to remember that life is not an all-or-nothing game. If we fail to live up to our highest potential in one moment, we can learn from that and move forward. If we enjoy the benefits of our kind and generous actions and words, we can learn from that, too. Not by clinging to past deeds, but by knowing with a growing confidence that this is how things work.