You can compare life to basically anything. A roller coaster, a camera, a beautiful melody, a piano, a mountain and all that stuff, but then I went to the beach recently and thought:
Just like a beach, life gives us waves.
Waves of joy,
Waves of sadness,
Waves of terror,
Waves of challenges.
But every waves brings new things, shells and fishes. Just like how life gives us circumstances and accomplishments.