RE: self-discipline 
"Never impose on others what you would not choose for yourself."
It’s the "Golden Rule" and the essence of real compassion . Not compassion as in looking down on someone and have pity for another, this is no real compassion. Compassion means seeing another person 100% equal to yourself (in value, not in differentials on the surface which ultimately do not matter). In fact it is seeing yourself in every other person. And therefore you cannot harm anyone without also harming yourself.
It doesn’t mean to lose individuality or self-worth, on the contrary – but the other person earns the same gift.