"Osteoporosis is like having termites in your house. You really don't know you have them. It's a silent disease. You don't know you have it until you start breaking apart."
Gradually the waves erode the foundation.
Lots more in the linked page.
METAMIA is a free database of analogy and metaphor. Anyone can contribute or search. The subject matter can be anything. Science is popular, but poetry is encouraged. The goal is to integrate our fluid muses with the stark literalism of a relational database. Metamia is like a girdle for your muses, a cognitive girdle.