t was back in the early 1980s that Mr Gardner, then aged 27, and his toddler son were homeless for a year in San Francisco. Enrolled on a low-paid trainee scheme at a stock brokerage, he didn't have enough money to raise the deposit to rent an apartment. So Mr Gardner, who was estranged from his partner, and Chris Jr would instead sleep wherever they could.
In addition to the toilet at a railway station, they'd bed down in parks, at a church shelter, or under his desk at work after everyone else had gone home. They ate in soup kitchens, and what little money he had was spent on putting his son in day nursery so he could go to work.Despite this adversity, Mr Gardner thrived in his job. A natural at selling stocks and shares, at the end of his training period his firm, Dean Witter Reynolds (DWR), made him a full employee.
Finally able to rent a home for himself and his son, his career then rapidly ascended into the stratosphere, and in 1987 he opened his own investment firm, Gardner Rich.
He now spends 200 days a year travelling the world speaking to packed audiences in more than 50 countries.
Scott Burns, a director at US investment firm Morningstar, says that Mr Gardner "is just an amazing testament of fortitude".
He adds: "You can be down and out, but only as down as you let yourself be."
Mr Gardner believes he disproves the theory that we are all products of our childhood environment.
"According to that school of thought I should have become another alcoholic, wife-beating, child-abusing, illiterate loser."
Instead he says he made his own positive choices thanks to the love of his mother and support from other people.
"I chose light, from my mother, and from others with whom I don't share a single drop of blood, and I embraced it."