How can Al-Hassan and Al-Hussein be the masters of the youth of Paradise when all the people of Paradise will be young? And does the Hadith indicate the existence of those who are not young in Paradise?

The noble Hadith: "Al-Hasan and Al-Husayn are the masters of the youth of the people of Paradise" means that Al-Hasan and Al-Husayn are the best among those who died young in the cause of Allah from the people of Paradise, or that they are the masters of the people of Paradise, with the exception of the Prophets and the Rightly Guided Caliphs. This is because all the people of Paradise will be in their youth.