A young man without ambition is an old man waiting to be. - Steven Brust

A stupid person can make only certain, limited types of errors; the mistakes open to a clever fellow are far broader. But to the one who knows how smart he is compared to everyone else, the possibilities for true idiocy are boundless.

Why do you work so hard to make yourself disliked? I should think you'd find it happens enough on its own without putting yourself to any extra trouble.

When there's nothing you can do except worry, that's a good time to worry.