Why Pray For Everyone's Happiness?

This is a very oft repeated Mantra in the Hindu temples. Its basic and inherent intention is very nice one and kind of universal. However, one has read Bhagwad Gita and understands the very basics of Vedanta would find that Sorrow and Happiness are illusions… and one who is similar in both the scenarios is the true yogi! Now, how can one ever know how to be tranquil if one has never come across sorrow? And can there be anyone – even the incarnations and the top Gurus – who has never faced sorrow? So, why pray for something that is a veritable impossibility? Instead, isnt it better to pray that "God, please help everyone deal with his/her sorrow when one encounters it and manage the happiness when it comes along!"??

For, in my estimation, those who get temporary happiness do not know how to "manage" it.. that is why they tend to become egotistic. And the ones who get sorrow cannot handle it properly… and the only "right" way to tackle sorrow or downtimes in your life is to realize that everything is temporary. Just as happiness is temporary.. Sorrow is temporary too. After all even the darkest hour has only 60 minutes!

Om Sarve Bhavanthu Sukhina
Sarve Santhu Nira Maya
Sarve Bhadrani Pashyanthu
Ma Kashchith Dukkha Bhaag Bhaveth

[Oh Lord, may all of mankind be safe,
Let no one experience pain or suffering.]

-Hindu mantra