别回头瞧那只跑掉的狗
[bié huí tóu qiáo nèi zhĭ păo diào de gŏu]
This translates to 'Don't look back at the dog that ran away'. Its deeper meaning could imply forgetting past unsuccessful relationships or failures rather than looking back on them, urging one to move forward bravely without being entangled by what can no longer be regained.