Oh yeah, there was a miss calculation of a financial information and I guess because of this stocks have fell. Why? Because some smart guys used Excel.

Or, then I can become a doctor right? By studying hard at home?

You should not employ a self thought software engineer or statistician or a doctor in critical positions such as health, finance, engineering, and science. Some might be okay but 99.9% of them will be incompetent for the work.