Just imagine, a guy comes to you fresh out of college, you give him years of training, and just when they really understand things, they tell they are leaving.
你想想看，一個人大學剛畢業進公司來，你要給他幾年的訓練？有人待了十幾年，剛剛懂了，會做事了，卻告訴你他要走了。