If Kevin O'Leary had a time machine and a phone plan that worked across decades, he'd have exactly one message for his 25-year-old self: "Don't change anything."

The "Shark Tank" investor and entrepreneur posted that reflection on Friday, explaining that every misstep and victory along the way became part of his DNA. "The good, the bad, the failures, the wins, that's your DNA," he wrote. "That's what gives you the experience to avoid the wrong path and stay on the right one."

Embracing Mistakes as Assets

O'Leary, often called "Mr. Wonderful," wants young professionals to stop fearing mistakes and start viewing them as foundational experiences. Those failures, he argues, are what teach you which paths to avoid and which ones to double down on. It's a counterintuitive take in a world obsessed with flawless resumes and LinkedIn highlight reels.

The Discipline Behind the Success

Earlier this month, O'Leary revealed what keeps him sharp at 71: early mornings, ruthless focus, and zero tolerance for email distractions. His routine includes tracking global news, biking, working out, and intermittent fasting. He also applies a "signal and noise" framework he picked up from Apple Inc. (AAPL) co-founder Steve Jobs—essentially, cutting through the clutter to focus on what actually matters.

Money Lessons from Mom

O'Leary's net worth reportedly tops $400 million, but he credits his mother's simple advice for building that wealth: never spend the principal, only the interest. That discipline stuck, even as he admitted to some regrettable purchases over the years—like extravagant cowboy boots and a Porsche he bought purely for fun. The sports car, he said, was "the most fun he's ever had spending money," though he acknowledged most Americans can't afford those kinds of mistakes.

The takeaway? Even Mr. Wonderful has buyer's remorse sometimes. But the bigger lesson is about embracing the full journey—boots, cars, failures, and all.