Why is the mother given the highest respect in our society?

Someone asked Swami Vivekananda 'why is the mother  given the highest respect in our society?'.

Swami Vivekananda replied,".I'll give u the answer tomorrow.". 

He then took a piece of stone and wrapped it in a piece of cloth without letting the man see what was in it.  He told the man ,"in the meantime , take this piece and tie it around your  waist for one day. Don't see it and come back to me tomorrow.". 

The man went away and continued his daily chores but the stone was weighing heavily on him. Finally he could bear it no more.  After a few hours he went back to Swami Vivekananda and told him to  remove the weight from around his stomach as he couldn't bear the discomfort. 

Swamiji  took off the load from around his waist, opened the cloth and showed him the stone and said, "this is your answer. You could not carry this small load even for a few hours but a mother carries a baby in her womb for nine months  happily and without  complaint. Now you understand why she is given the  the topmost place of honour  love and respect?