A 2018 study published in an edition of The Lancet: Child & Adolescent Health could change the way we think about child development, adolescence, and millennials forever.

According to the research presented, you may be of legal age to buy a drink or rent a car when you turn 21, but your brain isn't technically done growing up until you're 25 years old.

Currently, when people refer to someone as an adolescent, most of us equate the term with being a teenager, i.e., anyone between the ages of 13 and 19, and while some also include the preteen or tween years, i.e., 9 through 12.

However, Professor Susan Sawyer of the Royal Children’s Hospital in Melbourne and her team of fellow scientists know the definition of adolescence should be extended, beginning at the age of 10 and lasting all the way to 24.

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Given that the millennial generation is loosely defined as beginning with anyone born between the years of 1981 (or 1982) through 2004, this means that some of you, my millennial brothers and sisters, may in fact, still be stuck in your adolescence.

If you are a person in your early 20s, your reaction upon reading this is probably something along the lines of, "Man... I don't think so. I'm hella grown!"

Whereas for those of us millennials who made it past our 20s and on into our 30s, not to mention our big brah and sis Gen-Xers (now in their late 30s through 40s) and those self-righteous Baby Boomers, the findings of this research are likely far from revelatory.

When I think about some of the nonsense I got myself into in my early 20s, all I know is that it's not only a miracle I survived, it's a miracle I didn't wind up in jail — or worse... living back at home with my parents!

What is truly fascinating, however, is the reasoning behind this proposed change in definitions.

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The results of Sawyer's study indicate that human brain development continues well into our 20s.

. And beyond that physiological date, it also turns out that as more people are staying in school longer on average in order to get advanced degrees, they are also holding off on many of the so-called milestones of life — such as a grown-up, such as getting married, becoming the head of a household, and having children — until much later in life.

Seldom have I ever read a piece of news that has made me feel so gosh darn good about my current lot in life.

As an unmarried, childless woman in her early 30s, it's easy to feel like you're falling behind the bell curve.

If a group of elite scientists is suddenly willing to stand up on behalf of me and everyone else in my generation to claim they have proof that I'm just as average as the rest of my slacking cohort and that our brains are simply wired this way, listen — I am ready, willing and eager to believe every single thing they have to say on the subject.

If millennials seem immature to you, the study also posits that this is because of the role social media takes in all of our lives these days.

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It's not that millennials are less mature than any generation that has ever come before them, it's that we've always been this way, but we couldn't see it all so clearly before the onset of a culture in which our lives happen in an increasingly public way and are then shared across a variety of social networks.

As the authors of the study wrote:

“Arguably, the transition period from childhood to adulthood now occupies a greater portion of the life course than ever before at a time when unprecedented social forces, including marketing and digital media, are affecting health and wellbeing across these years... An expanded and more inclusive definition of adolescence is essential for developmentally appropriate framing of laws, social policies, and service systems.”

Should the medical community widely adopt an extended definition of adolescence, it's unlikely the change would have any meaning from a legal perspective, but it would definitely make it a heck of a lot easier to mock your younger cousin for her questionable fashion choices: she can't help it, she's an adolescent, after all. (Or maybe that's just me.)

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Rebecca Jane Stokes is an editor, freelance writer, former Senior Staff Writer for YourTango, and the former Senior Editor of Pop Culture at Newsweek. Her bylines have appeared in Fatherly, Gizmodo, Yahoo Life, Jezebel, Apartment Therapy, Bustle, Cosmopolitan, SheKnows, and many others.