Dance challenges, lip syncs, recipes, pranks: TikTok contains all sorts of curious things. But the latest viral trend might be the strangest yet.

The video-based social media platform is full of people asking men a simple question: "How often do you think about the Roman EmpireLasting from 27BC to 476AD, the Roman Empire controlled regions around the Mediterranean in Europe, North Africa and Western Asia. ?"

The trend originated with Artur Hulu, an influencer who posts comedy sketches dressed as a gladiatorProfessional fighters in Ancient Rome. They were usually slaves or criminals. If they fought well enough, they could earn freedom. Gladiators fought against other people and wild animals.. He challenged women to ask the question to their male partners and relatives. After a few people responded, things snowballed. The hashtag #romanempire now has 1.1 billion views.

Many were shocked by just how many men think about Ancient Rome - and just how often. Some said "every day". One said "constantly." When one user doubted her brother's interest, he showed her a replica of the ColosseumA vast stadium built by the Roman emperors Vespasian and Titus. It could seat between 50,000 and 80,000 spectators. It was used to hold gladiatorial contests and even mock sea battles. he had spent several weeks building in MinecraftA 3D computer game in which players can build worlds using building blocks. It has been described as like "an online LEGO". .

An interest in the Roman Empire is nothing new. The ancient civilisation is a source of almost endless fascination. It left behind grand monuments and incredible poetry. And its violent sports and political intrigue have inspired countless novels, films and TV series. VictorianThe era when Queen Victoria was on the British throne, from 1837 to 1901.  poet Robert Browning wrote: "Every one soon or late comes round by Rome."

It has even influenced the modern world in numerous ways, through the languages we speak to forms of government. English uses the Roman alphabet. As classicistAn expert in ancient Greek and Roman language, literature, art, architecture, or culture. Mary Beard writes: "Rome is ingrained in our political, cultural and literary traditions, and ways of thinking."

But not all roads lead to Rome. The trend has encouraged people to share their "Roman Empire", the thing they think about all the time.¹ Many, especially women and non-binary people, have revealed their own secret preoccupations.

Basketball player Aliyah Boston said soca, a Caribbean musical genre. Playwright Sandy Rustin thinks about stopping gun violence. For comedian Natasha Vaynblat it is both alien life and motherhood. And for actor Ellen Adair, it is the Roman Empire's collapse.

Perhaps everyone has a secret interest that disproportionately occupies their mind.¹ The things we think about are one of the things that define us. Our interests form part of our personalities. They determine the activities we do, the books we read and the things we watch.

They also shape who we spend time with. People are attracted to those who share similar interests. As writer Jessica Klein says: "Various studies have shown friends and romantic partners tend to share core beliefs, values and hobbies".

Yet others claim there is much more to us than our interests. Not everyone has the luxury of time to ponder a historical period or political issue. Our personalities also include our reactions to others and emotional patterns, things that can have little connection to the things we like to think about.

Two people fascinated by Ancient Rome might differ in all other respects. America's Founding FathersThe men generally thought to have played the most important role in creating the United States of America, by leading its military forces during the War of Independence or by writing the documents on which it is founded and still guide the country today. and Italian fascistFollowing fascism, a set of ideologies that advocates dictatorial power, political violence, suppression of opposition, traditional gender roles, and official racism. leader Benito Mussolini shared an obsession with the empire. But few would consider them political allies.

Yes: Lots of things define us. But our interests have a particularly big influence on our lives. They shape the places we go, the people we meet, the views we form and the conversations we have.

No: The things that occupy our mind are important. But they define us less than our actions, the things that actually affect others and the world around us. No one is defined by their thoughts alone.

Or... Defining a person is a futile task. Each of us is a slippery mixture of thoughts and emotions, interests and instincts. We change all the time, sometimes gradually, sometimes moment to moment.