Kevin O'Leary has invested in Shark Tank for 14 years, and he says that the most profitable projects are often surprising. For example, Base Paws, a cat DNA testing tool, he initially thought was a joke, but it ended up selling nearly 100 million dollars. In contrast, those deals he was optimistic about didn't make much money later.

His core suggestion:

**About Startup Failure**: Don't be afraid of failure; in the entrepreneurial journey, failure is inevitable. The key is to learn from it.

**About Timing Investment**: Don't think you can time the market perfectly. He has tried countless times over the past 14 years and has failed. The market changes rapidly, and no one can predict it accurately. The only way is to diversify your investments.

**On Choosing Investments**: To be honest, you have no idea what a good investment is. Those seemingly perfect projects may be mediocre, and absurd ideas may explode. Therefore, it is essential to diversify your portfolio and spread the risk.

Key takeaway: "You simply can't time the market. Diversify, that's what matters."