AHP's correct. The Axis' OTL success is at the far extreme end of the probability curve. During the early years of the war they were almost impossibly, consistently, lucky.
Yet they had their abundant share of missed chances and bad decisions that paved the way to ultimate defeat. Some major ones:
-Decision to invade Czechoslovakia after Munich, which prompted Britain to give guarantee to Poland and lose all faith in Hitler's trustworthiness. Failure to develop a decent casus belli about Poland in the eyes of the world, by provoking them to do someothing rash in Danzig. In combination, these two caused Anglo-French intervention.
-Not letting the Anglo-French attack Norway first, which would have improved their reputation with neutrals and let them intervene with the acquiescence of Norway.
-Failure to destroy the pocket at Dunkirk, which let the Britain save the vast majority of their professional officers & NCOs, have troops to spare to defend North Africa & the Middle East (and intervene in Greece), not to suffer a morale-crushing defeat (which could have brought Churchill down), and led to the creation of Free France.
-Lack of timely acknowledgement that Britain is not going to sue for peace, and Sealion is impossible, and swift switching to a Mediterranean strategy. Major coordination and focus of Axis forces in the Mediterranean in Summer-Fall 1940 could have avoided the Greek war, netted Malta, an brought Axis forces at Suez at the very least, which could have brought Churchill down, prompted Spain and Vichy France to join the Axis. With the Axis at Suez, the Iraqi rise up against the British, and with availability of Syrian ports and airports, Axis troops may be sent to support pro-Axis rebels, which denies Iraq oil to Britain and traps them in a strategic vise in Palestine (with the local Arabs rising up for Axis). Most reasonable outcome, the British lose Middle East, Churchill has a very high chance of falling, Axis has plenty of oil, Iran and concede me this point, Turkey have very good chances of joining the Axis, which is rather bad news for the USSR.
-Failure to discover Canaris' treason, which prevented Spain from joining the Axis.