Answer the question at the end by quoting:

Patrick John Neshek (born September 4, 1980) is an American professional baseball pitcher for the Philadelphia Phillies of Major League Baseball (MLB). He previously played for the Minnesota Twins, San Diego Padres, Oakland Athletics, St. Louis Cardinals, Houston Astros, and Colorado Rockies. The Twins selected him in the sixth round of the 2002 MLB draft from Butler University. Neshek made his MLB debut for the Twins on July 7, 2006, and played for them until 2010, except 2009, which he missed due to Tommy John surgery.
The Oakland Athletics traded for Neshek on August 3, 2012, for cash considerations, and immediately called him up from Triple-A Norfolk. To make room for Neshek on the roster along with same-day call-up right-handed pitcher Dan Straily, the A's optioned relievers Jim Miller and Evan Scribner to Triple-A Sacramento River Cats.  On September 22, Neshek gave up the game-tying home run in the bottom of the 13th inning to New York Yankees slugger Raul Ibanez. The A's had scored four runs in the top of the inning, leading to a galling 10-9 loss the next inning. However, the A's defeated the Yankees the next day and went 9-2 to end the season, edging the Texas Rangers out of the American League West championship by one game, including sweeping the final three-game series in Oakland. In 24 games with the A's, Neshek tallied  19 2/3 IP, yielding 10 hits and six walks, with 16 SO and a 1.37 ERA. He relied heavily on the slider, throwing it 83.5 percent of all pitches.  On November 30, 2012, Neshek avoided arbitration by agreeing to a one-year deal with the A's. He started the season well, posted a 2.34 ERA in his first 38 appearances into August, with 30 of them being scoreless. However, he gave up three runs apiece in two different appearances. Neshek attributed his early success to throwing almost exclusively sliders to right-handed hitters. Of all his pitches, he threw the slider 73 percent of the time in 2013.  The A's designated Neshek for assignment on August 26. For the season, he finished with a 3.35 ERA in  40 1/3 IP. He elected free agency November 5. Through the end of 2013, Neshek had faced 555 right-handed batters in his MLB career, holding them to a .181 batting average, .257 OBP and .315 SLG. In 326 PA, opposite-handed hitters, had more success with a .237 AVG, .328 OBP and .432 SLG.

Which team did he leave to join the Oakland Athletics?

Triple-A Norfolk.

IN: Theodor Seuss Geisel ( ( listen); March 2, 1904 - September 24, 1991) was an American author, political cartoonist, poet, animator, book publisher, and artist, best known for authoring more than 60 children's books under the pen name Doctor Seuss (abbreviated Dr. Seuss) (). His work includes several of the most popular children's books of all time, selling over 600 million copies and being translated into more than 20 languages by the time of his death. Geisel adopted the name "Dr. Seuss" as an undergraduate at Dartmouth College and a graduate student at the University of Oxford. He left Oxford in 1927 to begin his career as an illustrator and cartoonist for Vanity Fair, Life, and various other publications.

Geisel was born and raised in Springfield, Massachusetts, the son of Henrietta (nee Seuss) and Theodor Robert Geisel.  His father managed the family brewery and was later appointed to supervise Springfield's public park system by Mayor John A. Denison after the brewery closed because of Prohibition. Mulberry Street in Springfield, made famous in Dr. Seuss' first children's book And to Think That I Saw It on Mulberry Street, is less than a mile southwest of his boyhood home on Fairfield Street. Geisel was raised a Lutheran. He enrolled at Springfield Central High School in 1917 and graduated in 1921. He took an art class as a freshman and later became manager of the school soccer team.  Geisel attended Dartmouth College, graduating in 1925. At Dartmouth, he joined the Sigma Phi Epsilon fraternity and the humor magazine Dartmouth Jack-O-Lantern, eventually rising to the rank of editor-in-chief. While at Dartmouth, he was caught drinking gin with nine friends in his room. At the time, the possession and consumption of alcohol was illegal under Prohibition laws, which remained in place between 1920 and 1933. As a result of this infraction, Dean Craven Laycock insisted that Geisel resign from all extracurricular activities, including the college humor magazine. To continue work on the Jack-O-Lantern without the administration's knowledge, Geisel began signing his work with the pen name "Seuss". He was encouraged in his writing by professor of rhetoric W. Benfield Pressey, whom he described as his "big inspiration for writing" at Dartmouth.  Upon graduating from Dartmouth, he entered Lincoln College, Oxford, intending to earn a PhD in English literature. At Oxford, he met Helen Palmer, who encouraged him to give up becoming an English teacher in favor of pursuing drawing as a career.

how did he start writing?

OUT:
the humor magazine Dartmouth Jack-O-Lantern, eventually rising to the rank of editor-in-chief.