In Short: Youth will go. And if it goes being squandered, it results in thousands of calamities and pains both in this world and in the next. If you want to understand how the majority of such youths end up in hospitals with imagined diseases arising from misspent youth and prodigality, and in prisons or hostels for the destitute through their excesses, and in bars due to the distress arising from their pain and suffering, then go and ask at the hospitals, prisons and graveyards.
For sure, just as you will hear from most of the hospitals the moans and groans of those ill from dissipation and debauchery resulting from the drives of youth, so will you hear from the prisons the regretful sighs of unhappy youths who are being punished for illicit deeds mostly resulting from the excesses of youth. And you will understand that most of the torments of the grave —that Intermediate Realm the doors of which continuously open and shut for those who enter it— are the result of misspent youth, as is testified to by those who have divined the life of the grave, and is affirmed by the people of reality.
Also, ask the elderly and the sick, who form the majority of mankind. Certainly, the great majority of them will say with sorrow and regret: "Alas! We wasted our youth on passion and fancy; indeed, harmfully. Be careful, do not do as we did!" Because, as a consequence of the illicit pleasures of five to ten years' youth, a person suffers years of grief and sorrow in this world, torment and harm in the Intermediate Realm, and the calamities of Hell in the hereafter. And although such a person is in a most pitiable situation, he in no way deserves pity. For those who freely consent to indulge in harmful actions may not be pitied. They are not worthy of it.
May Almighty God save us and you from the alluring temptations of this time, and preserve us from them. Amen.