I've been self tought since I was 13 years old, so 11 years as well. Used PS 7 to begin with.
When you start using PS for photography or design elements as well, you create work that is lightyears beyond any sig in terms of depth and actual use of the program, because you need to explore more of the program. I probably used 10% of what was available in PS before I started photography
Ous, Photoshop CS2 is free now from the Adobe website (Killz posted earlier in the tech section), download it and play around