In life we have many attachments and we are told that we should develop the detachment . So we love food ,alcohol, and many other things that give us pleasures and we try to avoid the things that give us sorrow. But the problem that what we think will give us pleasure also give us sorrow when we do not get them .I want a cake and I don't get it and then I am unhappy. So the cake is suppose to give me happiness - no matter how transient that is - i have sorrow for longer time when I do not get it. But the bworst is the attachment to our own body and our family. This is known to all of us . So this is the story related to this attachment.
Once Narad , who is a sage who can travel any place at will went to Lord Vishnu and told him that you want everyone to get rid of attachments but the attachment to our own body ,no matter how bad or disease ridden it may be, is strong and attachment to our own family is stronger . It is very difficult to get rid of it or develop detachment. The Lord Vishnu knew this but was not convinced that it was that strong . So then the Narad told him to see it for himself or experience it . So Lord Vishnu agreed. He told Narad that he will enter the body of mother pig and see if he can get out of the attachment . But he told Narad that after 3 months if he does not leave the body on own , then Narad has to stab the pig and get Lord Vishnu out . Narad agreed. Then Lord Vishnu entered the body of a pig . Time went by and 3 months passed . Pig had piglets and Lord Vishnu did not come out . So Narad called upon him saying that 3 months have passed and it is time to come out -get rid of the attachment to the life of a pig. The Lord Vishnu replied 'I am happy here and I don't want to end it and come out '. Narad waited for few more days then then again requested Lord to come out and Lord Vishnu refused to do so. So then Narad stabbed the pig and Lord Vishnu came out . Looking at the whole thing -the life of a pig - Lord agreed that it is very very difficult for Human beings to get detached from the body and the family.
