I was emailing with one of the local mountain bike fast guys today and I said I need to spend some more time in the dirt if I’m going to be competitive in mountain biking. But to me getting on the mountain bike feels like work. I can spend hours on the road and it’s a joy and most of the times, doesn’t feel like a job. But, when I swing a leg over the mtn bike it’s like punching in. He said he feels the same way about riding on the road.

After countless hours of hard training year after year and your cyclocross obsession, mtb is work? Sounds like mind over matter to me..
It’s a little of that, but road and cross are so different then mountain.
Road is legs and lungs. Mtb is total body abuse. Road fitness helps, but there is no substitute for hitting the dirt — it’s a different world.