You should get rid of your foolhardiness.

你必须改掉你的蛮干作风。

What he once took as boldness he will now judge as foolhardiness.

他以前认为的勇敢现在觉得是有勇无谋。

That determination o Arjuna, by which the unintelligent is unable to abandon dreaming, fearing, grieving, depression and foolhardiness is in the nature of nescience.

无法放弃妄想，恐惧，悲哀，沮丧和蛮干愚勇，他们的决心是处于愚昧无知的品性中。