The Zero was an amazingly fast and agile opponent, and it's quite understandable that the US pilots in their big clunky Wildcats and Avengers and Buffaloes felt hopelessly outmanoeuvred by them.
But the Zero was agile because it had no armour, unlike the Americans. It's like the old saying, "You may be lucky fifty times, but I only need to get lucky once".
The way America won the Pacific war was a wonderful illustration of why military preparedness - doesn't actually matter that much, if you're as large as that. The USA was actually better off for not having a large pre-existing military establishment - it meant it could gear up its unmatched industry and produce the right equipment for the war it actually found itself in, rather than one some strategist had dreamed up twenty years earlier. Japan never had a hope in heck of overrunning the USA - a brief glance at any atlas would have told everyone concerned that much - and without doing that, there was no way of stopping them from eventually out-producing Japan.