I am often asked to answer questions by students about life as an illustrator and my sources of inspiration, I sometimes don't get chance to respond to these questions, which are, invariably variations on the same line of inquiry.
Having just read a couple of other illustrators thoughts on the subject, I am inclined to agree with what they say and urge you to read and digest :
http://davidfoldvari.blogspot.com/2009/03/update.html
http://jodybarton.blogspot.com/2009/05/questionnaires-from-students.html
(ps. dont even get me started on magazines that offer tuition and step-by-step guides on "how to be an illustrator")