The lobster is a soft, vulnerable creature that lives inside a rigid shell. That shell protects it, but that same shell cannot expand.

As the lobster grows, the shell becomes confining. Pressure builds. Discomfort intensifies. When the pain becomes unbearable, the lobster retreats under a rock to hide from predators. And then, it casts off that shell, and begins producing a new one.

Eventually, that new shell becomes uncomfortable too. The pressure returns. The lobster goes back under the rocks. It sheds again. The cycle repeats throughout the lobster's entire life. Each time, growth. Each time, vulnerability. Each time, renewal.