.شَيئانِ لا يَعرِفُ فَضلَهُما إلّا مَن فَقَدَهُما : الشَّبابُ، وَالعافِيَةُ

There are two things whose worth is only known to one who has lost them: youth and health.

Ghurar al-Hikam, no. 5764