离题万里 [- - wàn lǐ]be remote from the subject; be too far afield; be too far from the subject [mark]; completely off the point; go adrift far from the subject; go wide of the mark; It hit a long way from the target.; miles away from the subject; There is a far cry to the subject.:
•¶ 下笔千言,离题万里。 A thousand words from the pen in a stream, but ten thousand li away from the subject.