The doctors I saw immediately diagnosed me as Type 2 and treated with Metformin. Between that, starving myself, and exercising like a maniac I was able to keep my blood sugar roughly under control for another year or so.
Then everything really went to shit and additional tests were like, "Whoops, guess it was Type 1 after all."
With doctors having a hard time getting past their own biases and experience, it's no wonder the average person does, too.