In the earliest stages of building a business, founders may shy away from dreaming big and make conservative estimates of how successful they’ll be. But DoorDash cofounder and CEO Tony Xu is now warning entrepreneurs not to cap their ambitions, like he once did.“I think a lot of times you kind of, as an entrepreneur, have to take the greedy algorithm,” Xu recently said on the Uncapped with Jack Altman podcast. “You have to keep going all the way and seeing if there’s more.”It’s a lesson he’s learned when trying to secure seed funding for DoorDash in the spring of 2013. Just months after the company’s inception, with only around 150 customers and $10,000 in sales, the four cofounders submitted an application to startup accelerator Y Combinator. When asked how much they think their business could make one day, the entrepreneurs gave an estimate that seemed aspirational in the moment—but pales in comparison to how much the $87 billion giant reels in now. “I estimated something like $100 million of revenue,” Xu continued. “Thankfully, we’re a few orders of magnitude off.”In reality, the company reached that annual revenue in 2018—and it’s only hit the gas since. DoorDash’s first-quarter revenue this year hit a whopping $4 billion, reeling in 40 times more than their original revenue projection in just a single quarter. And its success has exploded beyond its Silicon Valley roots. Total orders across America and more than 40 other countries have also increased 27% over that same time, amounting to 933 million.“It’s very hard as an entrepreneur when you’re working out of your apartment, to know what that size could be one day,” Xu said. “Turns out a lot of people eat food.”Founders say it’s important to be ‘delusional’ and ‘crazy’ Founders who have launched billion-dollar businesses are being candid on the methods to their madness. Whether it be “delusional” or “crazy,” many say embracing unconventional thinking is what helped them make it big-time. Chess.com cofounder Danny Rensch started his online empire when his life was on the brink of collapse. Although he initially believed his vision was unrealistic, he credits a bit of that self-delusion to the platform’s success. And after years of elbow grease and persistence, Rensch has scaled Chess.com as a go-to destination for digital chess and reached a $1 billion valuation in 2023. Now the beloved gameplay business hosts tens of millions of matches daily, with hundreds of millions of users tuning in from around the world.“The idea that Chess.com could actually be what I thought it could be required me to be delusional,” Rensch told Fortune last year, referencing the same wisdom as his friend, Bonobos cofounder Andy Dunn. “The belief that you see something that doesn’t exist yet, and how delusional that is, is the requirement for every successful entrepreneur.”Billionaire Mike Repole says that craziness is key to success. The serial entrepreneur cofounded and sold beverage companies Glaceau (Smartwater, Vitaminwater) and BodyArmor to Coca-Cola for a combined $9.7 billion. But along the way, he admitted that he “failed” multiple times; two-thirds of startups bow out within a decade, so it’s imperative that founders keep going, even when signs tell them to turn back. “The first five years for an entrepreneur I call the survival years. Every single day, you could go bankrupt,” Repole said in an interview with the School of Hard Knocks last year. “I started crazy…Crazy people change the world.”And he isn’t alone in his founder philosophy. George Arison, a longtime entrepreneur and CEO of the LGBTQ+ dating platform Grindr, told Fortune that being “arrogant and crazy” are prerequisites to succeed as a founder in America. Arison, who was born in the country of Georgia, owned up to being both of those things and being motivated by seemingly impossible feats. Now, Grindr boasts a market cap of $3.2 billion and is growing rapidly year over year. “One of my motives in life is doing impossible things; that’s how I’ve shaped my life,” Arison continued at Fortune’s 2024 Brainstorm Tech conference. “My whole life is impossible. I’m now here doing this, and look at where I was born. Nothing’s actually impossible.”This story was originally featured on Fortune.com