关于"I don't have no idea."那次看电影,听见一个人说"I don't have no idea.",字幕是"我不知道".不应该是"I have no idea.难道是我把"I do"听成""I don't"了?

关于"I don't have no idea."
那次看电影,听见一个人说"I don't have no idea.",字幕是"我不知道".
不应该是"I have no idea.
难道是我把"I do"听成""I don't"了?

两个都没有错,在口语中很多时候人们用双重否定表示否定.
eg.i ain't got nothing