Generate an example of a metaphor using the words 'time' and 'river'.
"Time flows like a river, endlessly moving forward, never stopping or turning back."
Complete the following task based on the instruction and optional input provided.### Instruction:
Generate an example of a metaphor using the words 'time' and 'river'.

### Output:
"Time flows like a river, endlessly moving forward, never stopping or turning back."