Basically from what I remember he belived that the actal trip was around 3800-4000 KMs and he basically made almost twice the distace just to land on cuba 6.700-7000 km and the actual distance to his destination is nearing 20000km (and that's just to Japan).
Now I can understand mistaking, but he basically assumed that the earth was 5 times smaller. From what I remember since ancient greece people managed to actually calculate aproximately how much the eart was big.
Was he simply Ignoring this information?
Was he "crazy" or self-illuded, that he wanted that much to make it that he lied to himself?
Also I remember almost a decade ago my History teacher alluded and implied that he lied to Queen Isabell about the real lenght of the trip in order to persuade her to get the funds, is this also a possiblity a bit?
I've written about Columbus' miscalculations of the width of Eurasia and the size of the earth here before; you can read more at this link.
Essentially, Columbus thought the earth was about 25 percent smaller in circumference than it is, and that Eurasia took up between 180 (Ptolemy's estimate) and 225 degrees of the earth's circumference (it's actually closer to 130). Furthermore, maps of the time showed "the Indies" (modern day Indonesia) extending much further east than they do, and showed Japan further east than that and nearly on the equator. If you'll forgive the Wiki link, this is a reconstruction of a map by Toscanelli that Columbus had access to; the actual continents are in light blue.
He also thought that the Azores, Canaries and Cape Verde islands were much further west than they are (and keep in mind those were spots he touched at on his outbound voyage) -- closer to the latitude of Labrador than they actually are.
So based on these miscalculations, he assumed the width of the Atlantic he'd need to cross was only about 3,200 miles (5,150 km); it's actually closer to 5,000 miles (8,000 km).
To answer some of your specific questions:
he basically made almost twice the distace just to land on cuba
He actually made landfall first on an island in the Bahamas, possibly modern-day San Salvador, but there are other candidates.
Now I can understand mistaking, but he basically assumed that the earth was 5 times smaller. From what I remember since ancient greece people managed to actually calculate aproximately how much the eart was big.
Five times smaller would be 20% the size of the actual Earth; as I said before, he miscalculated its size by about 25%, making his estimate for the Earth's circumference 75% of its actual size, not 20%.
And yes, you're correct that the Greeks estimated the circumference of the Earth; Eratosthenes of Cyrene (c. 276-194 BCE) had calculated it. Later estimates varied because of disputes over the length of the stadia Eratosthenes used.
Was he simply Ignoring this information?
Was he "crazy" or self-illuded, that he wanted that much to make it that he lied to himself?
I am not an expert on the psychology of Columbus, but he certainly took the most wildly optimistic estimates he could find to get funding for his voyage.
implied that he lied to Queen Isabell about the real lenght of the trip in order to persuade her to get the funds
Again, "lied" is a modern interpretation. His estimates for the size of the Earth went against common wisdom, but there's no real reason to think that he was being dishonest, just deluded. If he had thought he was actually sailing 20,000 km to Asia, there's no way he would have undertaken the voyage; European ships simply did not have the size to stock resources for such a long trip.
