Tim Ferriss asked Warren Buffett how to invest $1 million. Park it in an index fund, 'forget it and get back to work' was his advice.

• Tim Ferriss asked Warren Buffett and Charlie Munger for advice in 2008, a resurfaced video shows.
• The author and podcaster asked how they would invest $1 million as 30-year-old amateurs.

Tim Ferriss once asked Warren Buffett and Charlie Munger how they would invest $1 million as 30-year-old amateurs, a newly resurfaced video shows.

"I can't believe someone found this video!" the host of "The Tim Ferriss Show" podcast and author of "The 4-Hour Work Week" tweeted on Saturday. A Twitter user who goes by Compound248 posted the clip.

"My one and only time interacting with Buffett and Munger, and I was *intensely* nervous," Ferriss said. "2008 was also the first year I began seriously angel investing, as I felt I had no advantage in public equities."

Ferriss put his question to Buffett, the CEO of Berkshire Hathaway, and Munger, Berkshire's vice-chairman, during the company's shareholder meeting in 2008.

"If you were 30 years old again and had your first million in the bank, how would you invest it?" he asked. Ferriss told the pair to assume they were amateur investors with full-time jobs and enough savings to cover 18 months of expenses.

"Under the conditions you name, I'd probably have it all in a very low-cost index fund," Buffett replied, adding that he would expect it to outperform bonds in the long term. "Then I'd forget it and go back to work."

Munger agreed that parking the money in a fund tracking the S&P 500 or another stock index was the best option.

"If you don't have any rational prospects of being a very skilled professional investor, of course you should compromise on some simple thing like an index fund," he said.

Both of the billionaire investors underlined the rarity of their honest guidance in the finance industry.

"You will not get that advice from anybody because nobody gets paid to give you that advice," Buffett said. "You will have all kinds of people telling you how much better they can do for you than that, and how if you just give them a wrap fee, or give them commissions, or whatever it may be, that they will do better — but they won't do better."

The Berkshire chief added that amateurs shouldn't feel entitled to beat the market, as they're not putting in the time to become skilled investors or identify winning assets.

"You've got a very perfectly decent return over a 30- or 40-year period by doing what I suggest," he said. "Why should you expect more than that when you don't bring anything to the party?"

Ferriss told Insider in an email that he's kept Buffett's answer in mind over the past 15 years, and underscored its value to most investors.

"I have paid close attention to Buffett's advice — consider low-cost index funds and avoid high-cost salespeople — ever since," Ferriss said.

"I've made some exceptions for a handful of venture capital funds, as I know that world quite well, but I think he's right on the mark for the vast majority of cases and the vast majority of people."