Before Pearl Harbor, many Americans viewed Japanese (to the extent they noticed at all) as buck toothed incompetent Asians racially inferior. After PH, they suddenly were violent supermen with incredible martial powers.
Folks had a hard time grasping the logistical challenges in sending a fleet across the Pacific Ocean.
The IJN fleet after PH spent a good bit of effort attacking the British in India and Ceylon, an area of operations of somewhat limited strategic importance for them at the time.
And after the Doolittle attack, the Japanese then over reacted in turn.