Maybe the pros would feel this way if the road with me.
Ok, I am a reasonably strong rider for 53 and normally ride my 30-70 mile rides around 17-19 mph solo. No real hills rolling terrain. Probably in a group could ride a 5 hr century but never have solo. To me I see the pros riding 23-27 mph for courses that have much more elevations gains and I just cannot wrap my head around how they do this......great cyclist.
So I ride with my wife once in awhile. She has a good road bike rides maybe 10-20 miles at a time a few times a month. She averages 11-12 mph and getting up to 18mph is fast for her. I don't mind riding with her it is great. She does fine but inside my head I am thinking if we go any slower I going have trouble balancing. I struggle holding back on downhills with her and spin in the 23-34 gear up small hills so I do not get ahead of her.
So it occurred to me if I went out and did a ride with Ted King or some like pro they would think the same thing about my riding. In any case it was just a thought on how each cyclist has their own limits and training abilities.