Energy Invested

Why do we invest so much energy into individuals that cause no payoff for our investments? We give so much to those who drain us yet so little to those who drain us and sustain us. Is it that we like being used and creating another purpose for ourselves and find self-importance by creating a need for us in the lives of those we care for? Why do we spend so much time waiting in relationships? Waiting to meet someone. Waiting for replies from someone and waiting for the return on our investment of all the time we spent waiting. Why is it that those who make us wait KEEP us waiting? In that I mean: why do we wait on those we know will keep us waiting? Why do we stay and wait complacently without the feeling of enough self worth to stop waiting on others in order to act but act on our own regardless of whatever our actions may be. Do we say time was wasted once out investment doesn't pay off or is it that we always know we were wasting time and were only trying see how long we could go before we HAD to realize we were waisting the most nonrenuable resource we are give:TIME.