LOL.

Dont believe much of what you read on the internet, it's full of people who are unable to distinguish between reality and their dreams of winning the TdF.

I'm 57. I ride about five times your annual mileage. It is very unusual for me to cover more than twenty miles in an hour. Mostly, on a training ride with a decent amount of climbing, I might ride at 15-16mph. I don't think I'm slow. Not in the real world, anyway.