A friend of mine once said, "You know, I believe everybody can reach 5 Dan." However, he was probably referring to the minimum potential of each person, starting at a young age, etc.
I do believe most people can at least get 1d. 1d is really not much, not to insult anybody.
I don't think there's a usual plateau at 1d, it's just that some people randomly have blocks at certain levels.
There's nothing special about 1d, just like there's nothing special about star points. People only play on Tengen all the time as a middle game 'best guess' reduction move sometimes because they are attracted to the dot! It's just a dot! It's probably not the perfect spot for the reduction.
Here's proof of how arbitrary these 'plateaus' are. Once you get to 1d, I'm telling you now, unless you're abnormally optimistic, you'll think you are still very weak. If and when you get to 5 Dan, be it American 5 Dan (weak), Chinese 5 Dan (a lot less weak), or what have you, still, you will think you suck at this game and have a great deal of learning ahead of you. I'll tell you this very bluntly:
I'm 5 Dan KGS (usually ><) and in Canada, and 7 Dan on Oro... I suck badly! Still so weak! Yesterday, I actually read the kibitz of a Kyu player who said "They're so strong, I wish I could be like them one day." I admit that I was happy to read it, because I thought just like that like 3 years back when I watched 2 Kyu games with great awe, and asked them how to get so strong after the game.
Hehe, all ranks in Go are just as special as 1d or 5d, or 7d. I was very happy when someone told me I had leveled up to 24 Kyu.
To answer the original question of the thread - I boldly believe I can reach 7D/KGS9D/Pro level.
Take into account that, having recently finishing high school, I've been focusing my life on only Go. I play and do some studying every day, and I'm working a new job in order to raise funds for Guo Juan's learn Go in China thing. I also spent 5 months at KBC in Korea studying Go, until last December. I intend to continue my training for a few years more, if that's what it takes, focusing only on Go.
I started when I was almost 17. Too old! But it seems I can't complain
