Nothing cycling can give you the return that climbing can. Climbing is the ultimate in resistance training as far a cycling is concerned. Couple that with the suffering, whats not to love? As far as the mental game of climbing goes I like to tell myself while climbing that; Climbing hurts me because I am fat. ( It is true , 240 @6'-1'' thats plenty fat) I deserve to suffer like a dog on a climb because I let myself get so friggin' fat. But the more I suffer on these climbs the less fat I will be, so suffering is good. I must learn to embrace it. Suffering is good, it tells me I am not slacking and that I am working hard.
I also find faith in my abilitys and patience to help on a long climb. Faith that if I continue to put out the same amount of work for the appropriate amount of time that eventually I will arrive at the top. And that I have the patience to endure the suffering to get to the top.