Hitler and the Nazi leadership in general were making it up as they went along; they had no long term planning or backup plans in case things didn't pan out as expected. From 1933 until 1941, luck and good fortune were on their side, making all of their half-assed and improvised decisions look pretty clever and deliberate when they were actually all crazy 50/50 chance gambles that only worked because of fortunate circumstances beyond their control..
They were also supremely impatient and would change tactics/priorities based on what made for good propaganda and newspaper headlines declaring "victory!" coming, while losing sight of the larger strategic picture. He'd never authorize retreats, even though any good General will tell you a fighting withdrawal IS your best option sometimes. especially when you're up against foes that have the industrial power to outproduce you, every tank saved by being moved to the rear is one you don't have to rebuild from scratch in a factory thousands of miles away. Nope! Retreat? That's cowardice! And that would be bad for the look of the country, ignorant that it ultimately led to an even WORSE look for the country, T-34s in the streets of Berlin.
The decision to target the RAF early in the Battle of Britain, only to switch targets to urban centers that had vastly diminished military value because they weren't getting their promised-in-two-weeks air superiority as fast as they liked? Allowing the RAF to regroup and replenish their losses? Another example. Their early victories convinced them that if the enemy didn't fold in about a couple months at most, you were doing it wrong.....
How about the repeated times during the invasion of Russia? Ordering the changing of objectives when one particular town or pocket of resistance proved too tough to just roll over? Ultimately wasting time, fuel, supplies and blunting the spearheads of the armies advances until they were stretched so thin they couldn't reach anything? Or his decision to try and take or hold onto cities for propaganda value when they were already rendered useless since the Soviets moved the industry out ahead of the Germans, or it had already been bombed into the ground? The Sixth Army froze and starved to death at Stalingrad because to Hitler, REAL Germans don't give up ground, even if it's nothing but shell craters and rubble. I think you can blame his WWI sensibilities for that, he was convinced they could have won WWI if they'd just hung on to France harder, and was determined that he wouldn't commit the "Shame" of losing ground again, no matter what.
Arguably, Japan was just as reckless and bit off more than they could chew in the Pacific, interpreting the massive gains from initial surprise attacks as the kind of resistance they'd always face, only to find that when their enemies knew they were coming, they could leverage resources and manpower Japan couldn't hope to match against them. By the time that dawned on them, it was too late to ask for a do over, and the best they could do was try to delay the inevitable as they were pushed back. Also, like the Nazis , they were drawing strength from an internal ideology (Bushido, vs Nazism) that held they were the TRUE heroes of the fight and their superior will and spirit would somehow make up for the fact that US industry could produce 10 aircraft carriers in the same time frame that they could build one. Some of the more level-headed Japanese officers even had a name for this tendency to take wild gambles that flew in the face of military logic, hoping for some million to one win.... because glorious Nippon! : "Victory Sickness".
I see a little bit of this attitude every time some hillbilly with a plug of chaw in his mouth leans against his pickup and says he knows EXACTLY how to beat Isis...... if only them dumb pansy-ass liberals would let him..... Hitler and the Junta running Japan should prove pretty stark examples of why the armchair general is just that....