Since the dawn of the human race, we were nomads. Travel was a way of life and it has almost always sucked whether you've got your kids tagging along or not. Moving from one place to another was necessary as weather changed, as food sources lessened, as water became scarce, and of course to have a nice vacation from the everyday humdrum of trying to discover fire, hunting mammoth, running from saber-toothed cats, grunting at each other, and other monotonous activities.
The invention of the wheel and axle, the use of tools, and the domestication of animals soon allowed for swifter travel. Unfortunately, even at this early stage of our existence, that travel was still filled with freaking whining!