There are identical twins out there whose parents confused one with the other and now they living their life with the name of the other sibling, never noticing because it doesn't make any difference.

What I've found is that after a week socializing with twins, it's pretty much impossible to confuse one with the other, especially if they're older. There's always some little quirk that differentiates the two. The parents who raised them would have to be out of the world shitty if they can't tell apart their children.

I could see this happening when they are babies though. Like 6 weeks in Bob becomes Tom and Tom becomes Bob and you might never know. I don't think that would be harmful at such a young age though.
- Where I live, birth certificate registration require footprints taken by a nurse. I imagine identical twins still have different footprints pattern?
  
  Imagine when you're old and tried to compare your footprints out of curiosity only to find out your identity has been swapped this whole time.
- Yeah I can't recognize my own daughter in the first few weeks/months of her life even if I look at the pictures and know its her.
- As long as they don't have different allergies or had biometrics recorded and assigned to them at the hospital it arguably wouldn't even matter.
- Having had twins, I can't imagine it happening 6 weeks in for more than a few sleep deprived minutes. 6 hours, definitely. 6 days, maybe. But by 6 weeks, you know who is who. Even identical twins are pretty easy to tell apart after having spent significant time with them. It's actually pretty common for parents of di/di identical twins (which are the type that could be fraternal) to not think their twins are identical only to have everyone else notice they are.
- Yeah, there was an episode of full house with this idea - they used their footprints to tell them apart. I can imagine you couldn’t be doing that all the time tho.
Have siblings who are twins. Can confirm. In fact growing up with them it was weird to me that people got them confused with each other at all given how different they really are
Can confirm. During my whole primary school there were two twin girls in my class and me and all my other mates could tell them apart instantly but any other child in the school couldn’t. Actually we were quite surprised when they couldn’t because for us was quite obvious to differentiate them both.
This. I know identical twins, at first glance they look exactly the same, but with a little time it's pretty easy to tell them apart. Even in older photos it's not that hard to tell which is which.
- Me and the clone argue about old photos about who is whom. Like, WE don't know who WE are in some photos.
I have two boys who are not twins, 4 and 6, and I switch them up all the time. They don’t even look the same. One looks exactly like me and the other looks like if my wife were a man.

I just get my wires crossed all the time. I do the same with my two dogs (ones stocky and brindle and ones leggy and tan…both about the same height/weight though).
- That is fascinating! My dad always called me by my brother's name and vice versa. He would start with the wrong name and end with the right name, so it would feel like we both had two names.

That's why I tattooed my twins initials on their foreheads backwards at birth, that way if they ever forget who they are, they can just look in the mirror. Billy and Bobby will never forget who they are.

/s

Wait, what
- Woosh

There’s a This American Life story about a mom who was keeping track of which twin was which using diaper pins. When she took them in for a checkup, they changed the diapers for her and handed her the pins afterward. So she guessed!

https://www.thisamericanlife.org/691/gardens-of-branching-paths/act-three-27

See that's why you gotta think ahead and brand one of them with the hot safety pin.

It's had to have happened at least once.

I feel like if I ever have twins, I'm going to stress about that more than is necessary. Like, documenting freckles or using a sharpie or something.

We painted their toe nails for the first month but even after about a week could tell them apart pretty easily. Their position in the womb and the birth means they can have quite different head shapes from one another. Also as another comment said, differences in personality are big and start surprisingly early.
- My best friend is a mirror twin. His brother cried a lot more as a baby. When they became toddlers his brother complained a lot more. Now as adults, his brother still complains and argues a lot more. I don't understand how they can be genetically identical, have the exact same upbringing, and be so different from the moment of their birth, but they are.
- Yeah was going to say, one or the both of them is going to have a 'tell' right from birth - head shape, a birth mark, hair differences... something.
- That's pretty impressive. Having twins sounds awesome.
Baby tattoos. Solves some issues. Causes some issues. Gotta figure out what matters more
- Causes some issues.
  
  Like when they start vaping at 1 y/o and their first words are about taking a "gap year" after Pre-K?
Why should it even matter? Once they're old enough to know their own names, they'll remember. And until then, it doesn't matter who is who.

As someone who has 14 month old identical twins, I was almost positive this would happen. We painted their tiny toenails to try and avoid that. At this point we they are different enough we can tell them apart. Everyone else struggles, but we can tell easily

I see, you choose the michael scott approach

Can confirm. Had to go back to check prints. Were then color-coded for life and I still don't wear reds or browns.

No, that's why they mark them on the head with permanent marker! /s

Write initials in the soft spot

Relativity

This reminds me so much of the twins in One Hundred Years of Solitude.