Where on earth did you ever get such a crazy idea? Sorry, but you are absolutely, totally, and completely incorrect. Artistic progress and breakthroughs can and do occur at any age. I've been very active in the art world for over half a century, and quite successful, thank you very much. But, unnecessary negative criticism from incompetent teachers can stop anyone in their tracks in their developing years. Drawing is a skill that can be, and is, taught. Innate talent and personal style is something else. In fact, I seriously doubt that "talent" is even a criteria. It's all about hard work and determination.
If someone has a real passion and interest in art/drawing/sculpture/photography, etc, there are no limits to what they can do. The link below (and there are probably thousands of them) is a good example, but I don't need the internet for this. I've seen so much great stuff w/ my own eyes by enthusiastic people who did not know they had "talent", it would make people's heads spin. All anyone needs is some positive encouragement and a little guidance. The sky and beyond is attainable w/ those two things. Goodness gracious, save me from experts.
http://www.huffingtonpost.com/2012/08/08/late-blooming-artists_n_1758135.html