"But do not of your own accord make your troubles heavier to bear and burden yourself with complaining. Pain is slight if opinion has added nothing to it; but if, on the other hand, you begin to encourage yourself and say, "It is nothing, – a trifling matter at most; keep a stout heart and it will soon cease"; then in thinking it slight, you will make it slight. Everything depends on opinion; ambition, luxury, greed, hark back to opinion. It is according to opinion that we suffer"
-Seneca, Letter 78