Fire...interesting sub-topic to this thread.
I don't know how many of those who are discussing early humans and fire discovery have ever actually spent time with the type of fire in question; lightning-strike fire burned low to embers. It would most closely resemble a camp fire vs. fire in a fireplace, etc. Perhaps you all have - or, perhaps some of you are "city folk", I don't know. I bring that up because it helps to visualize the scenario wereby fire would be "discovered" if you have actually been around it in the proper conditions.
As I said, I don't know the experiences of others here, but I have been in the situation before where fire was not just some pretty, intellectual exercise - let's cook hot dogs on it and then go home kind of thing. I have camped and been comforted in the cold. I have camped and would have given anything - anything to be near a fire's warm embrace. I have forsaken actual shelter before just to sleep in the open by a fire because that is what made it possible to go on and make it through the night. Nature is a cruel and heartless bitch that doesn't care if you are cold or hungry - or afraid of fire.
For anyone who has slept out of doors even one time in the chill of a spring or fall night, it is not at all hard to imagine that early man would - at any opportunity - overcome his natural fear of fire. Being cold, truely cold, to the bone, is a powerful motivator. Being warm is at the very most basic of what we need as a species to survive. We haven't been hairy beasts with warm fur coats for a very long time.
So....early humans had no time to experiment with "technology" because they were to tired? Huh? Because of ...what? That is the experience on the show Survivor so early humans were the same? Please. Attempting to draw comparisons between early humans and the cast of Survivor is, to me, laughable. Of course the Survivor cast has troubles in the wild - we are modern humans who live with modern experiences, for the most part. Ofcourse all of their energy is spent preparing food and just looking for ways to survive...that's the name of the show! It is contrived to be entertainment and does not reflect what it would be like if groups of people, from any period in human history, actually tried to work together as a society for the benefit of all. Each member of Survivor is trying to off the others.
Ofcourse early humans had time to contemplate the following:
1) fire make Og not cold at night. Og not like be cold. Og like fire. Feel good.
2) When Og hands cold, Og rub hands together. Make warm. Feel good.
3) Hands warm feel good. Fire warm feel good. Warm good. Rub things make warm?
4) What Og rub together also make warm? Sticks in fire. Rub sticks?
5) Rub sticks not make fire, but make warm.
6) Is nighttime. Og full belly with mastidon. Og think deep toughts. Rub sticks more.
7) Sticks still warm when rub. Rub sticks more. Rub sticks hard.
8) Sticks make smoke when rub real hard!
9) Rub real, real hard sticks make fire
etc.