The only worse thing than being sad is for others to know that you are sad.

“He awoke each morning with the desire to do right, to be a good and meaningful person, to be, as simple as it sounded and as impossible as it actually was, happy. And during the course of each day his heart would descend from his chest into his stomach. By early afternoon he was overcome by the feeling that nothing was right, or nothing was right for him, and by the desire to be alone. By evening he was fulfilled: alone in the magnitude of his grief, alone in his aimless guilt, alone even in his loneliness. I am not sad, he would repeat to himself over and over, I am not sad. As if he might one day convince himself. Or fool himself. Or convince others - the only thing worse than being sad is for others to know that you are sad. I am not sad. I am not sad. Because his life had unlimited potential for happiness, insofar as it was an empty white room. He would sleep with his heart at the foot of his bed, like some domesticated animal that was no part of him at all. And each morning he would wake with it again in the cupboard of his rib cage, having become a little heavier, a little weaker, but still pumping. And by midafternoon he was again overcome with the desire to be somewhere else, someone else, someone else somewhere else. I am not sad.”
--Jonathan Safran Foer, 'Everything Is Illuminated'