Before domestication, they had to follow the game animals around on their migrations, travel to find the edible plants and fruits, etc.
Even once horse, goats, and cattle were domesticated for their meat, milk, and fur (note this is separate from agricultural cultivation), humans had to roam in really large areas, from winter grazing grounds to summer grazing grounds as still well as following the game animals around.
I think traveling is a very ingrained behavior in humanity.