It takes awhile before certain parts aren't sore .
Also, as a runner you are aware of the tremendous benefits of hill and speed work. Those are easy 30 to 45 minute workouts that you should do during the week.
As cyclists (and runners to a lesser extent), we become too infatuated with distance.
Distance is great for seeing a lot of ground or prepping for a charity ride, but can be time consuming and obsesive in nature.
This is supposed to be fun. The hurt doesn't need to last for hours. That is what the speed and hill work are for.
I am in the process of changing my mileage I mentioned above to do just that.
Most of us on this board need to realize that we are never going to average more than 20mph and should try to enjoy this sport more.
I do it mostly because, for the most part, it makes me feel like a kid again. I run a simple set up and just ride.
That being said, I think it would be super cool to do some cross country bike packing shit.