• Kevin O'Leary shared five pieces of life advice with Business Insider.
• The "Shark Tank" investor warned against wasting money, getting distracted, and talking too much.
• "Mr. Wonderful" said new couples should talk money on the third date, and kids need to fly the nest.

Kevin O’Leary, the "Shark Tank" star who sold his software company to Mattel for $4.2 billion in 1999, shared some harsh advice on life and wealth in a recent interview with Business Insider.

Known as "Mr. Wonderful," O’Leary offered five nuggets of wisdom: Stop wasting money, focus your efforts, listen more than you speak, have the money talk on the third date, and ensure kids learn to fend for themselves.

Think before you spend

"Stop buying $7 coffees. Don't pay 40 bucks for lunch. Make it yourself," O'Leary said. "Ask yourself every time you're about to buy something: Do I really need this?"

"Look in your closet at all the clothes you don't wear," he added. "It's all crap you don't need, and that crap could have been earning you market returns of anywhere from 8% to 10% over your entire lifetime."

O'Leary said that, if historical returns continue, someone earning $70,000 a year who invests 15% of their monthly income in a diversified portfolio starting in their late 20s and continuing until 65 can expect to retire a millionaire.

Focus on 3 things you need to get done at work each day

Workers should ask themselves what three things they need to get done each day, and not allow anything to distract them from completing those tasks, O'Leary said.

“You’ll become very productive and a very valued employee,” he said. Filtering out the noise helps you to “avoid getting sucked down that vortex” and falling short of achieving your most important goals, he added.

O'Leary had some blunt advice for anyone who disagrees with the direction their bosses are taking the company in: “Get another job.”

Listen more, it's a 'superpower'

Many entrepreneurs have "huge egos" and "love to hear themselves talk," O'Leary said. But when they're talking, they're not listening to the market, their customers, their investors, or their employees, he said.

"You have to learn how to shut up," he said, describing listening as a "superpower."

"It's akin to having your ear to the rail and hearing the train coming down the track that's going to run you over," O'Leary said, adding, "To know to get off the track. That's what listening does."

Talk about money on the third date

New couples should talk about money early on, when both sides are clearly interested in one another but aren't yet blinded by love, O'Leary said.

"You get to a third date, after the second drink, bring up money," he said. "That's Mr. Wonderful's advice, and I'm always right."

He recommends couples sign a prenup before getting married as that "forces you to do due diligence" and find out if your partner is buying drugs, racking up credit-card debt, or comes from a bankrupt family.

"Nobody wants to deal with this stuff when you're in the euphoria of courtship," he said. "But it's the reason you're going to get divorced if you don't get it right."

Children need to leave the nest

O'Leary warned about the "curse of entitlement" that can bedevil the kids of wealthy parents.

He recalled his mother's words to him at his graduation: "The dead bird under the nest never learned how to fly." When he asked what that meant, she explained that she had supported him all the way through his education, but there would be "no more checks," and he would have to fend for himself.

O'Leary added that some rich kids were "screwed up" by being funded for too long, meaning they had "no reason to launch."

"The risk in their life has been removed. They've been guaranteed a free ride for the rest of their lives. They become lost in a sea of mediocrity. It's a disaster for them," he said.

O'Leary emulated his mother's approach with his two children, providing for them from birth through to the last day of their education. He recalled telling them, "Full ride, but after that, you'll become a dead bird if you don't figure it out."

• Kevin O'Leary dismissed a comparison between the AI boom and the dot-com bubble.
• The "Shark Tank" investor told Business Insider that AI generates measurable savings.
• He also said that "everybody got it wrong" on the impact of tariffs on the economy.

The AI boom isn't going to collapse like the dot-com bubble, investor Kevin O'Leary told Business Insider.

Many people, including Nobel economist Paul Krugman, fund manager Bill Smead, and entrepreneurship professor Erik Gordon, have compared the fervor around AI to internet buzz in the late 1990s and early 2000s, which ended with a stock-market crash.

But the "Shark Tank" investor and chair of O'Leary Ventures said AI wasn't "the same hype that the internet bubble was, because today, you actually can see the productivity and measure it on a dollar-by-dollar basis."

O'Leary gave the example of Fly Guys, a drone company he's invested in. Other companies can commission it to scan the tops of their buildings and deliver "AI-ready aerial imagery" to identify problems and automatically create work orders for them.

"That saves millions of dollars" for companies like Walmart or Home Depot with large commercial footprints, O'Leary said.

He added that such savings from AI may offset tariff costs and support high valuations for stocks.

Whether that's the case should be revealed in earnings over the next 12 to 18 months, he said.

O'Leary thinks tariffs aren't the threat many thought

Stocks plunged after Trump unveiled his plans for tariffs on "Liberation Day" in early April, but have since rebounded to record highs.

The recovery shows why investors should stay in the market during downturns "even though it's nerve-racking and nail-biting," O'Leary said.

The celebrity investor and self-proclaimed "Mr. Wonderful" said it can be costly to panic and dump stocks, adding he has seen investors miss out by doing this "over and over again."

He added that if an investor cashed out during April's sell-off, they missed the sort of returns they might expect over three years in just 88 trading sessions.

The S&P has gained around 27% from its low on April 8, and is around 12% higher than its level before the slump, far above the market's long-term annual return of about 7%.

The bounceback reflects greater "clarity" over tariffs, O'Leary said, adding some were "very manageable" at 10% to 15% for trade partners such as the EU. The latest rates range from 10% for the UK to 41% for Syria.

The SoftKey founder, who sold The Learning Company to Mattel in 1999, said that he would have expected to see evidence by now if tariffs were going to reignite inflation or cause a recession.

The benchmark consumer price index rose only 0.2% in April, 0.1% in May, and 0.3% in June on a seasonally adjusted basis.

He said the fear that tariffs would lead to "input costs killing gross margin" hasn't been realized yet, and US consumers also look to be in good shape.

He called it a "remarkable situation" as "basically, everybody got it wrong" on the impact of tariffs on the economy.

O'Leary said that he and his business managers were loading up on inventory in preparation for a busy holiday season. "So that gives you some indication, we're net bullish," he said.