I've driven tractors on various gliding sites to haul gliders around and to pull out launch cables. As others have said, there are a few different things - hand throttle and hi/lo ratio - that actually make it easier to drive than a car.
It's strangely relaxing, too, as everything seems to be in slow motion.
It really is not difficult, and to prove it some women can do it too!
(I'll get me hat and coat)
SD