If we choose an external marker as the measure of our inner worth, whether it is the amount of money we make, or others' opinion of us, or the success of some project we're involved in, sooner or later we're bound to be battered by life's inevitable changes. After all, money comes and goes, and thus is an unstable source of self-esteem, an unreliable foundation upon which to build our identity.
Reality is devoid of any intrinsic identity that can be captured by any one single proposition - that is what Buddha meant by "voidness."
