hindsight       
noun [ U ] uk/ˈhaɪnd.saɪt/ us/ˈhaɪnd.saɪt/
 事后聪明,事后的认识
the ability to understand an event or situation only after it has happened
  With (the benefit/wisdom of) hindsight, I should have taken the job. 事后一看,我真应该接受那份工作。 
 In hindsight, it would have been better to wait. 事后看来,等一等会更好。