Because you can't argue with all the fools in the world. It's easier to let them have their way, then trick them when they're not paying attention.

I warn you, Eragon, beware of whom you fall in love with, for fate seems to have a morbid interest in our family.

The debate raged on for so long, at last Saphira had interrupted with a roar that shook the walls of the command tent. Then she said, I am sore and tired, and Eragon is doing a poor job of explaining himself. We have better things to do than stand around yammering like jackdaws, no? ... Good now listen to me. It was reflected Eragon, hard to argue with a dragon.

Consider non your superior, whatever their rank or station in life. Treat all fairly or they will seek revenge. Be careful with your money. Hold fast to your belief and others will listen." he continued at a slower pace, " of the affairs of love ... my only advice is to be honest. thats your most powerfull too to unlock a heart or gain forgiveness. that is all i have to say"Garrow to Roran p 64

Life is both pain and pleasure. If this is the price you must pay for the hours you enjoy, is it too much?

We are about to change history, said Saphira. We’re throwing ourselves off a cliff without knowing how deep the water below is. Ah, but what a glorious flight! (Eragon to Saphira)

It is foolish to conjure up woe where none exists.