If you dream you’re one half of identical twins, or one of fraternal twins, it is not good. If you can recognize who the other twin is, it means that in waking life, you’re feeling the stress and consequences of competition. Sometimes, you are competing against yourself. Your alter ego urges you to do better as you strive for perfection. No matter how hard you try, you feel as though you’re not good enough. Dreaming of twins means you face rivalry, either with someone, or the force within yourself.
There are rare instances where you were one half of a set of twins, but your other twin has died in the womb, in infancy/ childhood/ adulthood. Then your dream of your twin could mean different things. Such dreams could be triggered by memories and nostalgia.