I am convinced that there was a great deal more travel, exploration, and trade between early civilizations than we give them credit for. We all tend to think in terms of a Dark Ages European peasant family living in a hut, but it wasn't like that at all-- civilizations rose and fell with regularity. Periods like the peasants in the hut did occur, but there were other periods of a high degree of civilization, and we tend to foreget that.
I agree. I even suspect that "some" of those civilizations were sufficiently old to have been around during the last Ice Age, and their sites are now well-submerged. I find the notion that there was at least one such in the East Indies/Malaysia area that is theorized to have been the source from which civilization spread from into Egypt and Mesopotamia, was well as lesser known examples further east--the diaspora having been initiated by the flooding of the home of the "core civilization" at the end of the last Ice Age. I think there are one or two articles here at FR that allude to this.
A lot more seafaring happend. The miration to Australia 560,000 years ago makes that clear.