how do you lose your citizenship?
0 was adopted and his citizenship and name changed permanently
No record exists that 0 ever legally changed his name back to Obama. Records do exist that show he maintained his foreign nationality to get into college.
“how do you lose your citizenship?”
To become a naturalized citizen of another country, you have to swear allegiance to that country and that removes you as a citizen of your original country.
So, if a person from another country is in the US and wants to become a naturalized citizen, he/she will have to swear allegiance to this country instead of the country from whence he/she came and is no longer a citizen of the original country.
My grandson, due to having an American father and English mother, has dual citizenship which was registered at his birth. If he were to run for certain offices in either country that requires him to have allegiance to only that country, he would have to swear allegiance to that country to renounce his US or English citizenship.