Why are so many Americans so stupid, ignorant and gullible? By the way, I do love and admire the best of them

Stupidity is abundant worldwide, so is ignorance and gullibility and therefore, Americans do not have a monopoly on this at all. However, as an American myself, who have traveled the globe around a few times, I would say that I find a large majority of Americans as the most brainwashed society on earth. That is, severely conditioned by corporate America and by politicians on a daily basis, from birth to death and with no relief/hope in sight.