26-year-old Jen* was with her ex-boyfriend for over eight years. They were childhood sweethearts, first becoming a couple when they were 17, before breaking up in May 2024. “I was the one who decided to bring it up,” she says, adding that she’d been mulling over the decision for around a year. “He hadn’t done anything wrong. We had just fallen into the cliché of being ‘more like roommates,’ and no matter what we did, it wasn’t changing.”

Initially, making the decision felt like “too huge of a thing to handle”: the pair lived together and their lives felt inextricably intertwined. For months, Jen pushed the idea of parting ways to the back of her mind. “It was easier to stay,” she reflects. “Then it started to be a little harder to ignore.” One spring day, a few months after turning 25, she was driving to work when she felt overcome with an urge to take action. “[I thought], ‘I have to do it this evening’ all of a sudden,” she recalls. “I got home from work, we had a 20-minute conversation, and that was it.”

Jen isn’t alone in gaining newfound clarity shortly after turning 25. ‘Frontal lobe development’ – the point at which the brain supposedly maxes out on maturity, allowing for better reasoning and decision-making – has rapidly gained traction as a hot talking point online over the past few years. On TikTok, tongue-in-cheek videos about the changes people have made after reaching 25 often rack up millions of views: from switching to kitten heels to lasering off tattoos to, yes, breaking up with long-term partners. Model and author Emily Ratajkowski, who married her now ex-husband in her mid-20s, even posted a video earlier this year warning women against choosing a long-term partner before the development of their frontal lobes.

“It’s funny because when I was going through it in my head, I’d say to myself, ‘this is because your frontal lobe has developed’,” Jen recalls. “When I told the girls, they all said the same. When I told my parents, I remember my dad saying he could tell I was starting to become more sure of myself.”

Of course, despite the idea of frontal lobe development entering common parlance over the past few years, it’s not true that you wake up on the morning of your 25th birthday magically instilled with brand-new wisdom. “The frontal lobes are developing and changing throughout our lives, from birth to death,” says Paul Burgess, professor of cognitive neuroscience at UCL. “Everything we experience, and think, changes our brain.” Still, there is a lot of truth in the idea that people change a lot throughout their 20s, and often get better at thinking rationally. “There are some mental processes supported by the frontal lobes that reach peak performance for many people in early adulthood,” he adds.

Plus, there’s the simple fact that more life experience begets more wisdom. “Our 20s are often the time of our lives where we are having the greatest number of new life experiences in the shortest period of time that we might ever experience at any period of our lives – leaving our childhood home, getting a job or career, meeting new people and learning a huge range of new skills, being given new responsibilities,” Burgess continues. “I think it is likely that when people are describing their frontal lobes suddenly ‘maturing’ in their 20s, this is probably largely ‘code’ for the effects of life experience upon the way they understand themselves, others, and their place in the world.”

And as you mature, it’s natural for your approach to relationships to change. “Your 20s are a decade of immense personal growth and change,” adds dating and relationship coach Kate Mansfield. “People are still figuring out who they are and what they want in life, and it's not uncommon for partners to ‘grow apart’ as their individual paths diverge. This is a time when people’s priorities and life goals start to solidify. Essentially, you’re not the same person at 28 that you were at 22, and it’s natural that your relationship needs will evolve as well.” This chimes with research from dating site Match.com, which found that the average woman finds their life partner at the age of 25, and the average man at 28.

28-year-old Dan also went through a break-up in his mid-20s. Like Jen, there was no big, concrete reason for the split – no infidelity, no seismic betrayal of trust. “No one did anything wrong. It ended with a lot of love and respect between us both,” he says. But as time went on, it became ever clearer to Dan that the relationship had just run its course. With his late 20s on the horizon, he gained some much-needed perspective. “There were times in my early 20s where I felt like I had lots of clarity on who I was and what made me tick at the time, but looking back I think: ‘did I really know?’,” he reflects. “My perspective and priorities have shifted a lot.”

Jen also notes that her priorities started to “shift” in her mid-20s as she realised she had agency to make positive personal changes. “I think I became more selfish,” she says. “Even outside of the relationship, I realised that if I didn’t want to do something, then I didn’t have to. My priority was making sure I was doing things for me and caring less about what others thought.”

This makes a lot of sense to Mansfield. “With age and experience comes a clearer understanding of what you truly want and need in a partner,” she says. “This self-awareness, combined with the confidence that often comes with getting older, makes it easier to communicate your needs and boundaries. You’re less likely to waste time in situations that aren’t fulfilling because you value your time more and have learned from past mistakes.” Essentially, it’s little wonder that so many people cut and run from their partners at a time when they feel much more ‘secure’ in themselves.

That said, the process of becoming a clear-sighted adult with a firm understanding of all your wants and desires doesn’t begin and end at 25. In recent years, there has been no shortage of fictional stories which centre on transformative experiences had by women during midlife – Halina Reijn’s film Babygirl, Miranda July’s novel All Fours – which have resonated deeply with middle-aged, female audiences who have felt similar urges to derail their lives during perimenopause and beyond. Evidently, it’s never too late to shake up your life – and liberate yourself from your dull boyfriend.

*Name has been changed