Apparently there's a very specific age when you'll start to feel like an adult.

Image: Suddenly 30 was a little too real.

Birth certificate, bills, driver’s license: all the paperwork in my life tells me I’m a bona fide grown-up.

Yet much of the time I feel like Tom Hanks in Big — a kid who woke up one day to find herself playing ‘house‘ and going to ‘work’ and generally pretending to know how to adult.

Evidently these fraudulent feelings are common, because a new study out of the UK has found people don’t tend to feel like adults until they hit the age of 29 — a good 11 years after you’re legally considered one. So, essentially, being in your twenties is like being in limbo.

Fly Research asked 2000 people aged 18 and over what they thought were the ‘signs’ of official adulthood. Turns out it has nothing to do with the number of candles on their birthday cake, but rather whether they’d achieved certain milestones.

“What people really believe constitutes being an ‘adult’ are actually significant life events that give them adult responsibilities. Up until that point, regardless of their actual age, they are still perceived adolescents," Dr Frank Furedi, a sociologist from the University of Kent, told The Independent.

Here are the top 10 'Welp, I guess I'm an adult now' moments the subjects identified:

1. Buying a house

2. Having kids

3. Getting married

4. Having a pension

5. Becoming "house proud" (i.e. looking after the appearance of your house)

6. Life insurance

7. Being stoked about spending a night in

8. DIY projects

9. Hosting a dinner party

10. Having a joint bank account

So, how many did you check off?

I'm not quite sure about some of these. For instance, I am always secretly thrilled to spend a night on the couch with DVDs, or hosting dinner parties for that matter, but I think that has more to do with being a homebody than being a sign the 'GROWN-UP' part of my brain has finally been activated.

Actually, my personal marker of adulthood will be the day I whip up a batch of biscuits/cupcakes and at least 90 per cent of the batter makes it into the oven. Everyone knows real grown-ups don't enjoy frivolous things like cake batter — their diets consist of fancy delicacies like caviar and smoked salmon.

Here are some additional, arguably more accurate signs you're a grown up, according to The Glow team. (Post continues after gallery.)

As for the factors that made people feel like kids masquerading as grownups, here are the top 10:

1. Being financially dependent on parents

2. Living at home longer

3.  Playing computer games

4. Watching kids' movies

5. Watching cartoons

6. Being afraid of taking on grown-up responsibilities

7. Not wanting a "real" job

8. Wanting to travel

9. Having young role models

10. A lack of life experience

Really? If being a grown up means losing the desire to see the world and erasing Disney movies from my life, I'm not sure I want a bar of it.

Do you feel like an adult? Was there an exact moment that made you feel all grown up?