I used this calculator to compute the CAGR for the S&P 500 from 1995-2015. It calculated the average annual return to be 11.5% before inflation so roughly 9% after. You are correct that 10% is difficult but you can get really close.
Year 1: 100% gain Year 2: 50% loss
The arithmetic average here is 50%, which the geometric average is 0%. The CAGR listed is going the correct metric to use but that is not 9% after inflation using the date range you provided. I get 7.42% for 1/1/95 - 12/31/14 after inflation and dividends are factored in. Not bad by any stretch of the imagination, though!