Working out someone's age is always a dangerous game.
We've all been in an awkward situation when someone has asked us to estimate how old we think they are and naturally, you always guess at least five years younger than your actual guess.
However, even that social tactic isn't always safe when the ageing process varies so much from person to person and the world of football certainly isn't immune from the guessing game.
While football fans will never remember the exact ages of all their favourite players, you'd like to think they'd be able to make a good guess based on the length of their career and so forth.
But a recent Reddit thread has suggested that supporters are a little naive when it comes to certain players and we're pretty confident that you'll be surprised by some examples too.
Players with deceiving ages
From players being older or younger than most people thought to one player being older than another when everyone other it was the other way around, the comments make for very interesting reading.
Even we'll admit that some of the ages shocked us so much that we needed to check on Google only to find out that, yes, the player in question really is that old or young.
But enough chitchat, you can check out some of the examples that caught both us and the Reddit commenters out the most down below:
Kieran Trippier is nearly 30?
Sheesh. The most up-voted comment on the whole thread is certainly a surprising one, so clearly his England and Tottenham breakthrough happened a lot later in Trippier's life than we all thought.
Stephan El Shaarawy is only 27?
It seems like his legendary FIFA 12 card was making gamers rage quit an eternity ago, but you're telling us that he's still three years short of his 30th? Crazy.
Wayne Rooney and Charlie Adam are younger than Cristiano Ronaldo?
Let's just say that Rooney and Adam haven't aged as well as Ronaldo both physically and on the football pitch. Sorry lads.
Saul Niguez is only 25?
The fact Saul still has his peak years ahead of him is a scary thought for defences across Europe.
Phil Jones is only 28?
Credit to Jones because it feels like he's been playing at Manchester United for the last century, so the fact he's managed 224 games for the Red Devils before his 29th birthday is good going.
Alexandre Pato is younger than Jordi Alba and Marco Reus?
It's damning of Pato's decline at such a young age with AC Milan that, despite his career having long flown off the rails, the likes of Alba and Witsel are older than him at merely 31.
Thomas Muller is only 30?
It's been an entire decade since Muller bagged the World Cup Golden Boot. Combine that with the fact he looks very old for his age, has already started declining at Bayern Munich and Muller being shy of 31 certainly comes as a shock.
Alex Oxlade-Chamberlain is only 26?
Fair play to the Ox because his best years are still to come in spite of the fact it feels like he's been causing havoc in the Premier League for half a lifetime.
Georginio Wijnaldum turns 30 this year?
Whatever the Liverpool star's skin routine is, we want to know the secret.
Ryan Bertrand is 30?
It felt as though Bertrand was some sort of foetus when he took to the stage in the Champions League final, but just eight years later and he's closer to retirement than that night in Munich.
Aleksandar Mitrovic and Bernardo Silva are only 25?
Sorry guys, but you both look older than 25 and it's as simple as that.
Andrew Robertson is already 26?
Well, there goes us thinking that 'Robbo' was a wee nipper when he swapped Hull for Liverpool.
Willy Caballero is older than Petr Cech?
This might be the most mind-blowing fact of the bunch. Cech's long and historic spell in the Premier League makes it slightly incomprehensible that a late arrival in Caballero is in fact one year older.
Adnan Januzaj is just 25?
The day Januzaj scored two goals at Sunderland under the command of David Moyes feels like a bygone era, so it's pretty crazy to think that the United graduate is only halfway through his twenties.
Aaron Lennon is only 33?
It feels as though Lennon is ageing at a lower rate than the rest of us... it's easy to forget that his heyday with Tottenham and England came so early in his career.
Plenty of surprises
As you can imagine, we could go on and on listing the amount of surprises in the thread.
But if you're interested in reading about even more of them, you can check out the full comments section here.
We like to think you've been surprised by at least five of the players we've listed and let it serve as a reminder that not every footballer's age runs parallel to the traditional career path we've come to expect.