Chances are, if there's a LAN card in a gamer's computer, a copy of CS is installed. Inspiration, Experience and Solitude. Think of it as a kind of birthing. Ideas are conceived in inspiration. The artist then draws material from life experiences, nourishing it with knowledge and wisdom he already possesses, giving color and substance to what is gestating in his mind.
Solitude imbues it with a soul.
The artist internalizes, connects deeply with his work, refining it until it is ready to be brought out into the world. The thought of artists being sad people is largely because of these conditions. Artists come up with novel ideas when inspired. Memories and Life experiences which, more often than not, are laced with sadness, tragedy and pain. Solitude magnifies the effect of such conditions.