Louis A. Szekely (born September 12, 1967), better known by his stage name Louis C.K. (), is an American stand-up comedian, writer, actor, and filmmaker. He is known for his use of observational, self-deprecating, dark, and shock humor. In 2012, C.K. won a Peabody Award and has received six Primetime Emmy Awards, as well as numerous awards for The Chris Rock Show, Louie, and his stand-up specials Live at the Beacon Theater (2011) and Oh My God (2013). He has won the Grammy Award for Best Comedy Album twice.

C.K. was born Louis A. Szekely in Washington, D.C. on September 12, 1967, the son of software engineer Mary Louise (nee Davis) and economist Luis Szekely. His parents met at Harvard University, where his mother was completing her degree in a summer school program. They were married at St. Francis Church in Traverse City, Michigan. C.K. has three sisters. His paternal grandfather, Dr. Geza Szekely Schweiger, was a Hungarian Jewish surgeon whose family moved to Mexico, where he met C.K.'s Mexican paternal grandmother, Rosario Sanchez Morales. C.K.'s mother, an American with Irish ancestry, grew up on a farm in Michigan. She graduated from Owosso High School in Owosso, Michigan. She attended University of Michigan and graduated from Ohio State University Phi Beta Kappa. C.K.'s maternal grandparents were M. Louise Davis and Alfred C. Davis.  When C.K. was a year old, his family moved to his father's home country of Mexico, where his father had earned a degree from the National Autonomous University of Mexico prior to graduating from Harvard. C.K.'s first language was Spanish; it was not until after they moved back to the U.S. when he was seven that he began to learn English. He has said that he has since forgotten much of his Spanish. When C.K. left Mexico with his family, they moved back to the United States and settled in Boston.  Upon moving from Mexico to suburban Boston, C.K. wanted to become a writer and comedian, citing Richard Pryor, Steve Martin, and George Carlin as some of his influences. When he was 10, his parents divorced. C.K. said that his father was around but he did not see him much and when he remarried, C.K.'s father converted to Orthodox Judaism, the faith of his new wife. C.K. and his three sisters were raised by their single mother in Newton, Massachusetts. The fact that his mother had only "bad" TV shows to view upon returning home from work inspired him to work on television. C.K.'s mother raised her children as Catholic and they attended after-school Catholic class until they completed communion. C.K. has said that his father's whole family still lives in Mexico. C.K.'s paternal uncle Dr. Francisco Szekely is an academic and an international consultant on environmental affairs who served as Mexico's Deputy Minister of Environment (2000-2003).  C.K. attended Newton North High School, and graduated in 1985. He graduated with future Friends star Matt LeBlanc. After graduation, C.K. worked as an auto mechanic and at a public access TV cable station in Boston. According to C.K., working in public access TV gave him the tools and technical knowledge to make his short films and later his television shows. "Learning is my favorite thing", he said. He also worked for a time as a cook and in a video store.

Answer the following question by taking a quote from the article: How long did he live in mexico?
they moved back to the U.S. when he was seven