It’s Metaphor Week at the NDD!  First, a definition. A metaphor is a direct claim that
A is X.  A simile is similar, but it says A is like X, not A is X.

Want to stay young at heart?  Have not only the courage of your convictions, but the courage to explore them thoroughly.

 
Drawing and commentary 2025 by Marty Coleman | napkindad.com
 
Quote by F. Scott Fitzgerald, 1896-1940,  American author and screenwriter.  Ironically he died at the exact age of the older person in his quote.