Let me give you an example of how I used to draw when I first started out:
This is me when I though that my art kicked ass. My opinion was law and everything bad everyone said was just them being jealous of my talent:
http://img683.imageshack.us/img683/6986/hansel.jpg
And this is me when I wised up, got my foot out of my mouth and ears and listened to criticism that is needed to get better.
http://img24.imageshack.us/img24/4595/hanselredo.png
See the difference?