You feel dizzy and eveything gets dark. You blink, and your eyes adjust to the dimmer light of a large cave. Sunlight filters in from an opening about fifty feet away, and you can see about two dozen hairy, naked ape-like creatures. They are filthy and stink bad, with maybe six ugly children of various ages. None of them look old, though one is missing its lower right arm. You recognize the general look from science class - Neanderthals! Then you remember something else - the woman mentioned something about different times and places. Why would she send you back into ancient history with cave men?
You scratch absently at your crotch and pick a bug out of your own matted fur, then blink and look down. Oh, shit! You have the same scarred filthy body as the others - and it looks like you are one of the mature males! No parents, no school, and no pressure. The woman gave that to you, but now you are a beast who scavenges to eat, sleeps in caves, and pretty much lives like an animal. And as a mature male, you probably won't even live that long!
You grunt in surprise, unable to speak. It is hard to think clearly, but you are starting to 'remember' mating with some of the females, fighting with some males, knowing one or two of the ugly kids are yours. The scar on your right leg was from an animal attack. But you still remember your old life. And that sure looks way better now. You grunt again and turn to run back through the door, but all you see is the back of the cave.