Identical twins exist because a fertilized egg splits in two, and also to provide us with entertaining tales of mistaken identities. A recent Reddit thread vaguely asked for stories involving mixup with twins' partners, which while the premise of many a porn, also provided a platform for all sorts of funny twin stories.
These hijinks all would have been adapted into movies in the 90s, but now, just reading will do.
Was going down an escalator at a casino. Look across and see my brother! Get the excites and yell HEY BRO! Start waving for his attention!
Was waving to myself in a mirror.
I went to a funeral of a friend's father, I had no idea that the deceased had an identical twin. It felt really strange to see the guy in the coffin sat at the front row of the Church.