Stumbling upon previous work I've done puts a smile in my face. I never would've thought of it myself but I actually improved a lot. Only 3 years ago I was working on a Flash animation studio, with very little drawing skills and creatively stagnant. Now I'm working on several cool projects, and going through my own art curriculum! Competing with only yourself really works!
*Note: the second image was made by Arvalis at Newgrounds.com. We used it as a poster for the game we made - Ace Pilot.*