An Indian swami once wrote...

"You don't know how things were created, you don't know how things will end, all we know is that we exist right now, and there are rules."

That's more or less how it goes. I don't even remember what book it was from. All I know those lines kind of changed my life. It kind of ties in with the Golden Rule. Do unto others as you want others to do unto you.

If you punch someone, there is a likelihood they'll punch you back.

An added addendum, everyone has a right to pursue their own happiness as long as it doesn't impinge upon yours.

It took me 10 years to come up with this stuff, and now I pass it unto you. It has led me to happiness. :)