Did you ever think you are two persons together ?!

Human Chimera.

In a Greek mythology, a chimera was a fire-breathing-creature with physical traits of lion, goat, and dragon. In human beings, a chimera is a person who has two totally different sets of DNA inside their bodies.
Human chimeras were discovered with the advent of blood typing when it was found that some people have more than one blood type.
The one-way chimera occurs naturally when one unborn child absorbs the cells of another miscarried sibling in the womb, leading to the surviving person taking some of the genes of their “ghost” twin. That can lead to strange results in the DNA.
The individuals with chimera often don't know they are a chimera. For example, in 2002, news outlets reported the story of a woman named Karen Keegan, who needed a kidney transplant and underwent genetic testing along with her family, to see if a family member could donate one to her. But the tests suggested that genetically, Keegan could not be the mother of her sons. The mystery was solved when doctors discovered that Keegan was a chimera—she had a different set of DNA in her blood cells compared to the other tissues in her body.

Here are some examples of ways a person can become a human chimera.

It can happen after a bone marrow transplant.

A person can also be a chimera if they undergo a bone marrow transplant. bone marrow is the tissue inside our bones that are responsible for making white blood cells, red blood cells, and platelets. During such transplants, which can be used for example to treat leukemia. doctors use chemotherapy or radiation to destroy all the recipient's diseased bone marrow, then a donor's healthy marrow is put in its place.
The donor's bone marrow will keep on will keep on making blood cells that have the donor's DNA
according to a Scientific American report. That's how the recipient becomes a chimera.
In some cases, all of the blood cells in a person who received a bone marrow transplant will match the DNA of their donor, which called complete chimerism. But in other cases, the recipient may have a mix of both their own blood cells and donor one that's called "mixed chimerism."

It can happen during a normal pregnancy

More commonly, people may exhibit so-called microchimerism—when a small fraction of their cells are from someone else. This can happen when a woman becomes pregnant, and a small number of cells from the fetus migrate into her blood and travel to different organs.
One way simple way to prove this idea is to test mothers of boys who tragically died while pregnant or within one month of giving birth and see if they have any cells with Y chromosomes, which are only present in males. The researchers tested tissue samples from the kidneys, livers, spleens, lungs, hearts, and brains of these mothers. The study found that the women had fetal cells in all of these tissues.

https://www.nytimes.com/2015/09/15/science/a-pregnancy-souvenir-cells-that-are-not-your-own.html?_r=0

sources
https://www.sciencedirect.com/journal/european-journal-of-medicinal-chemistry
https://www.nature.com/articles/1704525
http://genetics.thetech.org/ask/ask208
https://www.nytimes.com/2015/09/15/science/a-pregnancy-souvenir-cells-that-are-not-your-own.html?_r=0