that makes sense..and the important thing is just riding....
A FG rider, I imagine (I tried it, this is from my FG experience) would approach nirvana in a state of much higher alertness, one that, for me at least, wouldn't be sustainable for more than 1 hour, two at best, after which I would be mentally exhausted. I am sure a FG rider will feel one with his bike and with the world, too, but coming from a completely different direction.
WHen i first built my (first) FG bike, my 'test ride' ended up being a 20 mile excursion along the Gulf coast w/ my wife while we were visiting family in FL. I didn't see..or dont' see, that is....a real limit to time or wearing because of concentration...it just becomes natural. What did happen though was about 4 hours later I went to put on the parking brake on our Suburban and realized that I couldn't lift my leg.....lol....the use of different muscles and the degree that FG riding is a different athletic experience became real clear right then & there!