He obstinately refused to change course and ended up ruining himself.
Tips
history
Found in 《梁书·武帝纪》 (Tang compilation by Yao Silian): '若执迷不悟,距逆王师,大军一临,刑兹罔郝' - originally warning rebels against persisting in defiance of imperial forces.
usage
Strongly negative and impatient in tone - used after repeated warnings have failed. Often follows 劝/警告/教训…还是 structures. The implicit request is 'wake up and change direction.'