My Mom and stepdad own 3 prime homes in 3 states, (Minnesota, Wisconsin and New Mexico), all owned free and clear. No mortgages, no re-finances. I guess they never got the memo about the "boom", they're old-school and risk-averse.
They worked normal jobs all of their lives and saved, they could have a Carrera GT and a Bentley GT in the garage now, but instead it's a VW NB convertible and a Subaru. They lived through the great depression.