It came in Hadith that a man's feet will not move on the day of resurrection, until he is asked four things: -concerning his youth, how did he grew old -concerning his life, how he spent it -concerning his wealth, how he acquired it and dispose of it -and concerning his knowledge what he did with it. And the prophet (S.A.W) said:"take advantage of five before five -your youth before old age -your health before sickness -your free time before your busyness -your wealth before your poverty -and your life before your death. Thats because these five matters are opportunities of deeds, strength, energy, seriousness and effort. And so if you waste it, then your life is at loss. That's because the actual true life of a person Is which he get it in the obedience of Allah. This is the actual true life.