Imaam Ibnul Jawzee (rahimahullaah) said:
Whoever ponders upon the end result of the worldly life will be cautious, and whoever is certain about the long distance of the journey (i.e. the hereafter) will prepare for the journey. How amazing is your affair O you the one who has certainty about an affair, but then you forget about it. The harm of the state of affairs is real, but you are unconscious of it! You fear the people, whilst Allaah is more worthy of being feared! You are overwhelmed by what you presume and not by what you are certain of. And among the most amazing of affairs is your happiness with beguilement and forgetfulness in amusement in that which will come to an end. You are deceived by your health and forgetful of the approach of illness. You rejoice with your well-being and are heedless of the close approach of agony. Indeed, the death of other than yourself should show you your death and the death bed of other than yourself has been made visible before (your)death. Indeed you are pre-occupied with your inclination towards pleasures (i.e. forbidden ones) and (diverted) from remembrance of the destruction of yourself. It is as if you have not heard of the news about those who have passed away and that you have not seen what time has done to those who have remained. And if you do not know, then those are their dwelling places and graves before you, destroyed by the winds.
[Source: Saydul Khaatir of Imaam Ibnul Jawzee’ page: 15-16. abridged and slightly paraphrased]