If you're in you mid to late 20s and still struggling to feel like a fully fledged "adult", don't stress - because according to science you only truly become a "grown up" in your 30s.
While in the eyes of the law, you're classed as an adult at 18, brain experts say this idea is "increasingly absurd".
In fact they note that the path to become an adult is different for each person, with some people becoming mentally mature much faster than others.
According to the Daily Mail, these new insights help show how the brain is shaped throughout a person's life, and the implications this can have.
It turns out that in our 20s we are highly susceptible to mental health disorders, which generally resolve once we get into our 30s.
Just this week, Professor Peter Jones, from Cambridge University, told media in London: "To have a definition of when you move from childhood to adulthood looks increasingly absurd. It's a much more nuanced transition.
"I guess systems like the education system, the health system and the legal system make it convenient for themselves by having definitions."
Jones added: "I think the system is adapting to what's hiding in plain sight, that people don't like a caterpillar turning into a butterfly.
"There isn't a childhood and then an adulthood. People are on a pathway, they're on a trajectory."
Professor Daniel Geschwind, from the University of California in Los Angeles, mentioned education systems mistakenly tend to focus on groups, not individuals, when each brain actually develops at its own pace: "These are larger questions that go beyond the science," Geschwind said.
"There are individual trajectories... development takes place over decades. But this varies from individual to individual."