There are alternatives to the white picket fence dream of ownership.
http://www.cbc.ca/beta/news/business/house-investment-wealth-1.3716641
I would guess that these people:
A) Had their parents pay for their education
B) Lived with their parents rent-free (and grocery expense free, etc.) while they saved up all that money
Even if you have two spouses with solid professional jobs, it's really hard to save up that much money that quickly if you have legitimate ongoing living expenses (rent, food, car, phone, internet, cable, etc.). Either that or they lived in a crappy basement apartment, ate Kraft dinner, and stared at the wall the whole time.