I know, now, that when one loses one’s good looks, whatever they may be, one loses everything. Your picture has taught me that. Lord Henry Wotton is perfectly right. Youth is the only thing worth having. When I find that I am growing old, I shall kill myself.

– Oscar Wilde

The Picture of Dorian Gray, Chapter 2. While Dorian Gray is known for his breathtaking youthful handsomeness, he is very conscious of losing all of that one day. He agrees with Lord henry that youth is the only thing worth having, and vows to kill himself before old age steals that from him.