To Fight Or To Smile?

on one hand, you must learn to fight and defend yourselves again oppressors. pyhsically kill and maim another human. imagine this... a world where every single soul is smiling... no fighting.. no bitching.. just pure caring.. now that would be a world that would take an infinite centuries to reach..every now and then you see people bombing each other... fighting and just holding grudges.. a thought came across my mind when thinking of charity workers.. if every one of were selfless and cared for just one person more than oursleves... and in turn another person care completely for you.. a give and take relationship.. wouldn't the world rotate more smoothly???