Answer by taking a quote from the following article:

Cohen was born on September 21, 1934, into a middle-class Canadian Jewish family residing in Westmount, Quebec, an English-speaking suburb of Montreal. His mother, Marsha (Masha) Klonitsky (1905-1978), was the daughter of a Talmudic writer, Rabbi Solomon Klonitsky-Kline, and emigrated to Montreal in 1927 from Lithuania. His paternal grandfather, whose family had moved from Poland to Canada, was Lyon Cohen, the founding president of the Canadian Jewish Congress. His father, Nathan Bernard Cohen (1891-1943), owned a substantial clothing store and died when Cohen was nine years old.

After two years of production, Cohen returned to music in 2001 with the release of Ten New Songs, featuring a heavy influence from producer and co-composer Sharon Robinson. The album, recorded at Cohen's and Robinson's home studios - Still Life Studios, includes the song "Alexandra Leaving", a transformation of the poem "The God Abandons Antony", by the Greek poet Constantine P. Cavafy. The album was a major hit for Cohen in Canada and Europe, and he supported it with the hit single "In My Secret Life" and accompanying video shot by Floria Sigismondi. The album won him four Canadian Juno Awards in 2002: Best Artist, Best Songwriter, Best Pop Album, and Best Video ("In My Secret Life"). And the following year he was given Canada's highest civilian honor, the Companion of the Order of Canada. In October 2004, Cohen released Dear Heather, largely a musical collaboration with jazz chanteuse (and romantic partner) Anjani Thomas, although Sharon Robinson returned to collaborate on three tracks (including a duet). As light as the previous album was dark, Dear Heather reflects Cohen's own change of mood - he said in a number of interviews that his depression had lifted in recent years, which he attributed to Zen Buddhism. In an interview following his induction into the Canadian Songwriters' Hall of Fame, Cohen explained that the album was intended to be a kind of notebook or scrapbook of themes, and that a more formal record had been planned for release shortly afterwards, but that this was put on ice by his legal battles with his ex-manager. Blue Alert, an album of songs co-written by Anjani and Cohen, was released in 2006 to positive reviews. Sung by Anjani, who according to one reviewer "...sounds like Cohen reincarnated as woman... though Cohen doesn't sing a note on the album, his voice permeates it like smoke." Before embarking on his 2008-2010 world tour, and without finishing the new album which had been in work since 2006, Cohen contributed a few tracks to other artists' albums - a new version of his own "Tower of Song" was performed by him, Anjani Thomas and U2 in the 2006 tribute film Leonard Cohen I'm Your Man (the video and track were included on the film's soundtrack and released as the B-side of U2's single "Window in the Skies", reaching No 1 in the Canadian Singles Chart). In 2007 he recited "The Sound of Silence" on album Tribute to Paul Simon: Take Me to the Mardi Gras and "The Jungle Line" by Joni Mitchell, accompanied by Herbie Hancock on piano, on Hancock's Grammy-winning album River: The Joni Letters, while in 2008, he recited the poem "Since You've Asked" on the album Born to the Breed: A Tribute to Judy Collins. CANNOTANSWER

What did he do after he left the monastery?

After two years of production, Cohen returned to music in 2001 with the release of Ten New Songs,