The thing that got him started was the price of gold had doubled just a couple of years before his first book. People thought they needed gold because stocks were in the doldrums and had been for several years.
What happened next was that Ronald Reagan got elected in 1980 following 4 chaotic years under President Jimmy Carter, which included the oil embargo, very questionable tax shelters sold to investors, union domination, and 12 % inflation. By 1982, people started believing in Reaganomics and the stock market took off like a rocket and didn’t stop until 2000. Meanwhile, gold dropped and stayed down for 25 years until this latest run up. So the lesson learned was to avoid putting all your financial assets in to a single investment and don’t get caught up in what could turn out to be nothing more than a fad. Bonds and stocks have factories and products behind them, but gold just has glitter and its price is set by the whims the speculators. A fund that invests in a broader basket of commodities that includes oil, agriculture, and other minerals, such as the PIMCO Commodity Real Return Fund, is a much safer bet.
And one last observation, for every reputable gold dealer, there are 10 wheeler dealers out there that will sell at a price way over the market price and buyers who will take advantage of anyone in the market to sell. Invest in gold or silver if you wish, but put it on someone you care for.