The Nazis were crack addicts!

[abaris]

That kind of thing has been accepted knowledge for a while, as far as I know.

Not as far as I am aware. If you mean by accepted knowledge that they popped pervitin as if there was no tommorrow, I agree with you. There was even a nickname for that drug amongst the soldiers. "Panzerschokolade". But the reason for the early stages of the war being that successful is the fact that the allies still fought the war of 1918 whereas the Germans fought the war of 1940. Amphetamins are supposed to be uppers and would make you more reckless, but looking at the casualty numbers of the Polish as well as the French campaign, nothing points to that. In fact, for the day and age, the Germans were losing very few soldiers in these campaigns.