Why Are There So Many Real Estate Millionaires?

A couple I know in Sydney who got married in 1972, they bought a house which cost around $100,000. At that time, it was a very expensive property and they could only afford to buy it because their parents helped with the deposit. They lived in this house for 28 years, until 2000 when they divorced. As part of the settlement, they sold the house and split the money. The result: they were both millionaires