人不為己？

小時候，記得人們試圖批判： 人不為己，天誅地滅！！提倡人人為我，我為人人。Or,  為人民服務。。
這可能嗎？ 兒子6 歲，可小心眼不少。 平時跟他老爸玩，他老爸不讓他，他輸了。
他就會跑來告賬： Daddy is bad.
我答：what did he do?
兒子,    he is not easy on me!! He does not let me win!!! 
我答： What can I do?  
兒子：  I hate him. 
我答：  I hate him too.  What can we do?  Lets kick him out!! 
兒子:      No, no, no, I do not want to kick him out!
我答：   Why not?   You dont like him. 
兒子:      Yeah, but I do not want to kick him out, because, at least he can go to work, he makes money for us .               Otherwise you have to work.... I do not want you to work..... you stay home and you can take care of me.

你看：這仫一個小東西，處處想的是自己？ 這難道不是應念了：人不為己，天誅地滅， 嗎？