A Mississippi teenager who became one of the youngest law school graduates ever in May is now setting his sights on reforming US tax law and taking on social media companies over claims they design their products to be addictive - and therefore harmful - to youths.

“What they’re creating is extremely predatory and harmful, and yet they’re sending it out knowing that it’s … harmful and not really taking any action to reduce the harm or address it,” 18-year-old Jimmy Chilimigras said of his interest in social media litigation. “You have a duty to protect people from harm, and if [you] breach that duty, and that breach causes these people damages … you should be held liable.”

Chilimigras shared those ambitions in a recent interview with the Guardian, in which he also detailed his unusual educational journey - including becoming the world’s youngest certified public accountant (CPA) and, given his age, ordering milk or cranberry juice at law school functions where his classmates opted for alcoholic beverages.

Growing up in Bay St Louis, Mississippi, Chilimigras showed signs of high intelligence early. He could speak in full sentences at age two and was homeschooled through high school, completing textbook-based courses at his own pace with his parents’ supervision. He earned a high-school diploma at 12, when most US students are in middle school. By 15, he had attained both a bachelor’s and a master’s degree in accounting via online coursework.

Chilimigras acknowledged that experience was atypical - and, as far as he sees it, that’s perfectly fine. “I think learning being asynchronous, where different people are allowed to move at different paces, is really valuable,” he remarked. “I think one thing that modern education gets wrong is just having everyone moving at the exact same pace, no matter their life circumstances - who they are, what they’re interested in or what their ability is. I think that’s a mistake - and that we are losing out on potential because of that, and a lot of people [are] being forced to do things that they shouldn’t be.”

From there, Chilimigras tackled the CPA exam - four parts, each about four-and-a-half hours long - studying about a month or two for each part, and earned recognition as the youngest CPA worldwide. He then aced the law school admission test (LSAT) with a score of 174 out of 180, all before his 16th birthday, enabling him to enroll at Louisiana’s Loyola University New Orleans, about 60 miles from Bay St Louis.

His law school experience was, predictably, unique. He carpooled to classes from the family home he shared with his father (a real-estate manager), his mother (a broker), and six younger siblings. His reputation preceded him thanks to national news coverage, with strangers approaching him just to see the prodigy in person. “There were a bunch of people who would say hi to me, and they’d know my name and a little bit about me - and I’d never seen the person before,” Chilimigras said.

His age was also an inevitable topic of conversation. In one class, a professor lectured about when police have reasonable suspicion to detain a motorist - such as the smell of marijuana emanating from a car. The professor posited that “everyone knows what the smell of marijuana is” before glancing at Chilimigras and retorting to laughter, “Well - maybe not you.”

The age gap was also evident at gatherings with bars, where his classmates ordered alcoholic cocktails, wine, and beer. Chilimigras initially asked for milk; after being told by befuddled bartenders they had none, he switched to cranberry juice as his go-to request. Despite the circumstances, he said his law schoolmates and professors mostly treated him like any other student.

Amid that environment, he ranked in the top 2% of his class, earned the highest grade in 40% of his courses, and graduated with highest honors on 10 May. A list by history and culture website oldest.org suggests he could be among the four youngest people worldwide to have obtained a law degree. Loyola touted him as the youngest law school graduate ever in Louisiana, which joined the US in 1812.

His graduation day ended with another reminder of his atypical path: he went home after his Loyola law commencement and supported one of his childhood friends, of the same age, by attending the friend’s graduation - from high school. It was the first time Chilimigras had ever been to a traditional high school graduation ceremony. “I guess it kind of hit me [there] a … bit,” he admitted.

After a family Caribbean cruise to celebrate, Chilimigras began studying for the bar exam and pursuing a master of laws (LLM) degree in taxation from Northwestern University’s Pritzker School of Law in Chicago - farther than he has ever moved from Bay St Louis.

He has identified a couple of areas for his legal career. One is participating in litigation over whether jury trials should decide tax controversies (currently they don’t, though IRS encounters can “feel like criminal prosecution,” he said). He also wants to litigate over whether there should be exceptions to the 90-day deadline for contesting an IRS audit letter - currently there are none, even if “your lawyer was a fraudster and never filed your tax filing, or maybe your house burned down, or there was a hurricane, or the IRS letter never actually reached you.” He sees such issues as “a great area to do some good.”

Furthermore, Chilimigras could see himself partaking in litigation seeking to hold social media companies liable for instilling addictive behaviors in children. He got the idea from seeing how much time some of his siblings spend on such sites and apps, and from conversations with friends who describe being completely absorbed by social media. “They spend more time on it than they like, and they’ll tell me, ‘What this does to me - I don’t like it, but I can’t do anything about it,’” Chilimigras said. “It’s sad, so it kind of sticks with you a little.”