You don't have to be a Buddhist...

... to see the wisdom in these:

1.
Once there was a man on a long journey who came to a river. He said to himself: This side of the river is very difficult and dangerous to walk on, and the other side seems easier and safer, but how shall I get across?"
So he built a raft out of branches and reeds and safely crossed the river. Then he thought to himself: "This raft has been very useful to me in crossing the river; I will not abandon it to rot on the bank, but will carry it along with me."
And thus he voluntarily assumed an unnecessary burden.

This parable teaches that even a good thing, when it becomes an unnecessary burden, should be thrown away; much more so if it is a bad thing.

2.
Whenever a person expresses the thought of his mind in action there is always a reaction that follows. If one abuses you, there is a temptation to answer back, or to be revenged. One should be on guard against this natural reaction. It is like spitting against the wind, it harms no one but oneself. It is like sweeping dust against the wind, it does not get rid of the dust but defiles oneself. Misfortune always dogs the steps of one who gives way to the desire for revenge.

Well the first one teaches us to be selfish. Do not bother putting up with a person once you have gotten your use out of them. I like it.

The second one is a false analogy, but I still find myself agreeing with it. I like to think that the reason I strive not to be vengeful is because I am a kind and gracious individual, not because being vengeful is somehow self-harming.