Once prophet Mohammad (Peace be upon him) was sitting alone, suddenly an old woman arrived and asked Prophet Mohammad (Peace be upon him) that "will I go to jannah?" so prophet Mohammad (Peace be upon him) said that "no! Old people will not go to jannah". After hearing this old woman started crying. After watching her crying prophet (Peace be upon him) smiled and said that "in jannah everyone will become younger instead of older." So did you get the moral of this story? Well the moral of this story is that in joke also we should not lie.