Flotsam On A Human Tide

Why be good?
This question isn't nearly as easy to answer as you might think. Yes I know we've laws and social expectations and all that, but when all is said and done what's stopping you from doing the countless things you secretly craved yet managed to deny yourself?
In a recent Facebook status I observed that I have Love/Hate relationship with my moral compass. It's kept me from doing all kinds of things over the years, things that could hurt me, hurt those I love. More often than not I listen to it begrudgingly, yet listen I do, and today I am reflecting why?
I don't want to hurt people. That's front and centre. But that still leaves vast oceans of potential for nefarious behaviour? But then does it? Perhaps every action has a consequence, a subtle or not so subtle effect on the world around us. Is there something in me that just prefers to live without excessive deception, that seeks genuineness and transparency wherever possible? Note; we all live with a certain degree of deception, and if you doubt this might I suggest you're, err, deceiving yourself? I have days when I'm pleasant on the outside only, when beneath the surface I'm a seething mass of unpleasant thoughts and ill will. On other days I'm the polar opposite, bursting with warmth and a desire for the happiness of others. What's that about? Hormones?Chemistry? Some conflicting residual evolutionary element?
I know that my distant ancestors were less troubled with the kind of moral finesse we grapple with. They of course had a kind of morality, but it was a blunter thing, more easily bypassed by our core urges. These are urges we've all still got, of course, but over the millennia the scales have shifted, and for the most part they override the voices of what some refer to as our inner chimp.
We have, to be sure, evolved. And whilst we can still be cruel, selfish, greedy, and brutish, society will leave us in no doubt as to what it thinks. Perhaps then, we're all kind of exerting a tacit pressure on each other? Perhaps were all flotsam on an evolutionary tide with a kind of rough awareness? So then, that suggests to me that morality cannot evolve in isolation. It has to be transactional, born out of how we interact with each other. Now I'm not saying that the world isn't still full of horrors spilling forth from every creed and culture. Yet we're still oddly bound by a shared humanity, a shared something that kindles us somehow. So even when I look at someone I disdain I could never justify causing them real harm; and in my case I choose not to interact with them, or to keep interaction to a minimum. I'd never wish them bodily harm, although I'm not beyond hoping that they might learn a few emotional lessons along the way. This blog is going to spiral if I keep going. I hope you can see what an odd and uneasy relationship we have with our moral compass. The sailing isn't plain, the waters often murky. How could it be otherwise?