Extended metaphors

This task is about adding additional ideas to a metaphor.
A metaphor is a phrase or sentence that compares two things by saying something is something else. An extended metaphor develops that idea.
 
Below are two examples of food used as metaphors for life. Both metaphors have been extended with additional ideas.
 
Life is a donut. It's delicious when fresh but can get stale if left.
The hole in the middle is a mystery.
 
or
 doughnut-small.png
Life is a banana. You start out green and get soft and mushy with age.
Some people want to be one of the bunch while others want to be top banana. Sometimes you can slip up.
 banana-small.png

Question 1Change answer

Now write your example. You can compare life to anything you wish, then extend it with additional ideas.
You may use the planning space below to plan in, before beginning on the lines below.
Planning space
 
a)  Life is a 

Question 1Change answer

b)  Give a reason why writers use metaphors or extended metaphors.