Before Adam by Jack London — Read

There is one puzzling thing about these prehistoric memories of mine. It is the vagueness of the time element. I do not always know the order of events; -or can I tell, between some events, whether one, two, or four or five years have elapsed. I can only roughly tell the passage of time by judging the changes in the appearance and pursuits of my fellows.

Also, I can apply the logic of events to the various happenings. For instance, there is no doubt whatever that my mother and I were treed by the wild pigs and fled and fell in the days before I made the acquaintance of Lop-Ear, who became what I may call my boyhood chum. And it is just as conclusive that between these two periods I must have left my mother.