“Diary of a CEO ”Host“ ”Steven Bartlett Spills on Joining “Shark Tank”, What Kevin O’Leary Is Really Like and More (Exclusive)

0Steven Bartlett on ‘Shark Tank’Credit: Disney via GettyNEED TO KNOWSteven Bartlett opens up to PEOPLE about joining Shark Tank following his debut on Wednesday, Oct. 7

The entrepreneur and Diary of a CEO podcast hostreveals what Kevin O’Leary is really like behind the scenes and the advice Lori Greiner gave him before filming

Bartlett also shares his mom’s hilarious reaction to his latest TV venture after years of critiquing his investments on Dragons’ Den

Steven Bartlett was prepared to go head-to-head with Kevin O’Leary when he joined Shark Tank — but when he got on set, the notoriously outspoken investor caught him by surprise.

The British entrepreneur, 34, who became the youngest-ever investor on the U.K.’s Dragons’ Den at just 28 years old, made his debut as a guest Shark on the Wednesday, Oct. 7, episode of the ABC reality show. In an exclusive interview with PEOPLE, Bartlett reveals that he wasn’t quite sure what to expect from his fellow investors, particularly O’Leary.

“I’ve known Kevin O’Leary on the show for probably about 15 years. I think I started watching the show when I was 16 years old, and Kevin has one hell of a personality,” Bartlett says. “I thought maybe he might be the one that I end up in debates and clashes with, but off camera, he was such a gentleman. He knows how to take a joke.”

While the two did exchange a few playful jabs during Bartlett’s debut episode, the Diary of a CEO podcast host insists there were no hard feelings.

“There were a couple of back-and-forth moments. I think it was all in good spirit,” he says. “He can not only give a roast, but he can also take one.”

Despite having years of experience in the investor’s chair (Bartlett founded the social media marketing agency The Social Chain and became a millionaire by age 23), he admits he initially felt intimidated about joining the American series. “I think I was intimidated generally because I just didn’t know what to expect,” he explains. “But I have to say, all of my fellow Sharks were just unbelievably welcoming and kind, as were all of the production teams.”

That warm welcome helped his nerves fade quickly, and one fellow Shark in particular made sure he felt comfortable finding his footing.

Bartlett recalls Lori Greiner stopping by his trailer before filming to offer some words of wisdom. “She said to me that the most important thing is you just say how you see it, and you don’t mince your words, you don’t bite your tongue,” he shares. “If you don’t like something, just say you don’t like something and explain why.”

Greiner also encouraged him not to shy away from disagreeing with the other investors. “You really need to be comfortable with truly being yourself in every sense of the word,” Bartlett recalls her telling him.

The advice resonated with the businessman, who says it can be tempting for newcomers to follow the crowd rather than trust their own instincts.

“What makes a distinctive Shark is truly just being able to be yourself,” he explains. “The reason why you’re there is because you have a perspective that the others don’t have. You’ve lived a life the others haven’t lived, and that’s true for all of us.”

“Lori’s advice was really important to me because it sort of freed me from thinking that I had to be a Shark,” he adds. “Actually, I was there just to be me.”

And while Bartlett was already familiar with the pressures of making investments on television, he quickly discovered that Shark Tank operates at an entirely different pace than its British counterpart.

“Dragons’ Den is very British in every sense of the word, so we’re much more polite and patient, and we rarely interrupt each other,” he explains. “That means the pitches last, you know, two or three hours at times, but Shark Tank couldn’t be more opposite in every respect. It’s chaos.”

Bartlett jokes that he had to temporarily set aside his British manners to make himself heard.

“I watched a few test pitches before I went on set, and I had to sort of remove my Britishness, I think, to be heard,” he says.

“In the U.K., you can sit there for two and a half hours, and you speak as a Dragon maybe for 20 minutes at times,” he continues. “In Shark Tank, I don’t think you get more than four sentences, and the entire pitch can be 30 minutes long.”

Never miss a story — sign up for PEOPLE’s free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from celebrity news to compelling human interest stories.

“Things moved a lot faster. The numbers are bigger. I mean, everything feels bigger in America,” he says. “I enjoyed the intellectual challenge of Americanizing myself a little bit for the show.”

His first-ever pitch as a Shark also gave him an immediate taste of the show’s fast-moving negotiations.

During Wednesday’s episode, Bartlett found himself in the middle of a potential partnership with fellow investors Greiner and Kendra Scott as the entrepreneurs behind Pupstack weighed their options. When the founders asked Bartlett which woman he would prefer to partner with, he decided to leave the choice up to them.

“In the U.K., you might have deliberated that, and you might have had a big discussion about it, but in Shark Tank, you don’t have the time,” he explains. “So I just said, ‘None of my business. The entrepreneur is going to decide.’”

“Those collaborations have to happen in a millisecond,” he adds. “That was my first pitch ever as a Shark, so it was a good one. Lots of fun.”

But while Bartlett is adjusting to a new group of investors, there’s one person whose opinions on his business decisions haven’t changed: his mom. The entrepreneur previously revealed that his mother is an avid Dragons’ Den viewer who isn’t afraid to criticize his investments, and he tells PEOPLE that she still regularly weighs in on his decisions.

“My mum will call me out of the blue, and I guess a lot of mums check in on, ‘Have you been eating?’ or whatever, but my mum will call me and spend like 20 minutes telling me what she would have invested in and why,” he says.

“She’ll tell me some of the decisions she disagrees with, the investments that I’ve made,” he adds. “[Dragons’ Den] is her favorite show.”

While his mom is a dedicated follower of his television career, he says she’s less interested in his hugely successful podcast. “She actually doesn’t listen to my podcast,” he says. “I’m not even totally convinced she knows I’ve got a podcast.”

Watching her son on television has also become a way for his mother to feel connected to him when he’s away from home. “That is very much how my mum keeps up with me when I’m away from home, watching Dragons’ Den or Shark Tank,” he says.

And with Bartlett now appearing on another business competition series, his mom has plenty of new material to critique.

“She basically ran out of Dragons’ Den episodes to watch, so she’s very happy with me becoming a guest Shark,” he jokes. “She’s got more stuff that she can watch at night.”

“She’s watched some of these episodes I’m on 10, 20 times now,” he adds. “So I think she knows the businesses better than I do at this point.”