This is one of my favourite Neil Gaiman quotes. Thanks to Neil for his permission to illustrate it. 
You can hear the original quote in this video in which he offers advice for young writers:
https://youtube.com/watch?v=bpNb5NwxX_g
And if you haven’t already seen the inspirational commencement speech he gave at the University of the Arts:
For more info about Neil Gaiman and his work, visit http://www.neilgaiman.com/