This actually made TV in the States
In one of the classes I taught (before my time , though) there were two friends. One man was a little older by than the other, but they had moved to the same small rural town from opposite coasts, each independently found a job in the same nursing home and became friends. They had a ton of interests in common and really clicked. People used to joke they looked and sounded alike enough to be brothers. They thought it was hilarious and decided to take the nurse's aide class together.

During the segment on early childhood and how early trauma affects people, one guy offered that he understood about that because his mother had abandoned him and his siblings in a drug house when he was a toddler. It was a few days before someone discovered them.

His friend turns to him and exclaims, "Dude, me too!"

"Well, this was in Detroit back in 19whatever."

"Wow, in Detroit? Same as me, only I was so little I was in diapers. I don't have any brothers or sister. I think."

Now, when I heard this, goosebumps rose up my arms and I got a chill. I asked the teacher, man, what did you think? She said it still hadn't occured to her that maybe they were brothers. Duh.

They were brothers. All 6 or 7 of the family had been scattered amongst foster homes and had lost track of each other. Since then, the boys have found a couple sisters and are looking for the rest. I just searched for the episode and can't find it.
(TDub Nunc id vides, nunc ne vides on, Fri 9 Feb 2007, 22:05, Reply)