I had a period where i was pretty much road only, had moved to another city/state didn't know any trails, so bought a road bike, then I moved back home, onto old trails...well actually new trails in old area, but even before I did the move wasn't really riding much... so no fitness, no skills... couldnt hardly ride the trails, well not to enjoy them anyway, so just kept on road for a coupe of years, then slowly eased back into it, now Im riding mtb more than road.
Still enjoy the road bike, it's different, but still fun, but mtbing is my true love... although for the first couple of months this year I ran more than I rode either haha...then injuries, boo.