That has been my experience as well, but in my case, the required fitness level was the real stumbling block. It's a whole different dimension of aerobic fitness. Around here there is a mountain bike club that offers a basic skills class that was very helpful. Maybe there is such a group in your area?
I didn't really keep up with it--I only really get on the mountain bike to do the super fun Stinky Spoke ride on what is supposed to be the worst weather day of the year. I imagine if I did keep at it more consistently, it would get easier...
Rodriguez Adventure
Bacchetta Bellandare
HPV Gekko fx
Custom Rodriguez Tandem
2009 Specialized Tricross
2012 Trek Mamba