So now man was on the earth almost 4,000,000 years and didn't manage to leave a significant trace until the last 6,000-10,000 years. Yeah right.
I've lost count of the number of times that you've made the mistake of thinking that your personal incredulity and/or lack of knowledge actually counts as any kind of support for what you'd like to believe...
And yet again you've managed to pack many misconceptions into a single sentence -- quite a feat, but one you frequently achieve.
First, it is in no way accurate to label the hominids 4,000,000 years ago as "man", as you have mistakenly done so here. Just because an ape walks upright, that doesn't make him a man, although for some bizarre reason you seem to think that it does. Humans as we know them are no more than a few hundred thousand years old.
Second, you assert that early men and proto-men "didn't manage to leave a significant trace" -- this is utter nonsense.
Finally, you try to imply that modern humans "didn't manage to leave a significant trace until the last 6,000-10,000 years". Again, you're just being goofily ignorant. Countless stone tools, campfires, cave paintings, etc. have been found from well over 10,000 years ago, and indeed ranging up to several hundreds of thousands of years.
As for why mankind took a seemingly long time to develop agriculture, modern city-states, writing, etc., go learn something for a change and read Jared Diamond's Pulitzer-prize-winning book, "Guns, Germs, and Steel: The Fates of Human Societies". It's a remarkable book which is highly educational in many different ways, but one of the (many) issues it addresses will be a useful remedy to your current ill-informed incredulity: The author examines why agriculture, alphabets, nation-states, etc. are all much "harder" to start "from scratch", for many reasons, than might be immediately apparent.
The real surprise isn't how long it took mankind to develop these achievements -- it's that we ever did so at all (especially when the hunter-gatherer lifestyle was so successful for us for so long).
And the earth is only 6,000-10,000 years old because of that?
So you admit the earth is older than 6000 years?