How does insurance work?

John and Mary's house just burned down yesterday.

Mary called the insurance company and said, "My house was burned down and I want to get my money."

The insurance agent said, "Actually, our insurance doesn't work that way. We will check what you lost in the fire and provide you a new one, which is identical or similar to your previous one. "

Mary said, "Oh, I see."

Mary thinks a while and said, "Then, please just cancel the insurance policy on my husband."