That average speed is meaningless without context.
What do you ride (beach cruiser, time trial bike, single speed, mtb, unicycle)?
Where are you riding (up Alpe d'Huez, on a flat trail, downhill, indoors on a trainer)?
How long and often are your rides (10 min, an hour, 3 weeks straight; daily, weekly, once a year)?
What kind of health are you in (20s without any health issues, centenarian after 8 quintuple bypasses)?
How do you ride (all out til exhaustion, soft pedaling/coasting 90% of the time)?
Are you constantly being passed by other cyclists, and if so do you notice what's different between them and you other than speed (their riding position, cadence, clothing, the amount of noise coming from their bikes' drivetrain and brakes compared to yours, the amount of stuff they're carrying on the bike compared to you)?