That's 18,641 miles in a year.

If you averaged 12mph, that's 1,553 hours in the saddle.
or 129 hours/ month
or 32 hours each week.

If you averaged 15mph it's still 25 hours of riding each week.

Does this person have a job?

Or is his JOB to ride a bike?

That's a LOT of KMs, miles, or hours anyway you look at it.