By Elizabeth Landau, CNN

(CNN) - Dr. Alfredo Quinones-Hinojosa insists, "I just think of myself as a regular guy."

It's an incredible statement from someone who grew up in an impoverished Mexican village, illegally hopped the fence into California, attended Harvard Medical School and now works at Johns Hopkins Medicine as a neurosurgeon.

"I've never been one who declines adventure," he says.

Early life

The oldest of five children, Quinones-Hinojosa as a child had nightmares that he had to save his mother and siblings from fires, floods, avalanches, says his memoir, "Becoming Dr. Q," which he co-authored.

His interest in medicine may have stemmed from this sense of responsibility, along with his baby sister's death from colitis (the memoir is dedicated to her). At 6, though, he wanted to be an astronaut.

His father owned a gas station, and Quinones-Hinojosa worked there at age 5; his family lived in an apartment in the back. But as Mexico's economy took a dive, the business collapsed, along with the family's livelihood. Quinones-Hinojosa's father had to sell it for almost no profit. They later learned that gasoline had been leaking out of holes in the underground tanks.

The family used to eat meat once a week, but that became a luxury of the past. After the station was sold, they had to make do with flour tortillas and homemade salsa, he wrote.

Short visits to California's San Joaquin Valley, where Quinones-Hinojosa's uncle Fausto was a foreman at a ranch, gave Quinones-Hinojosa a glimpse into the United States - and the American dream. At age 14, he spent two months there pulling weeds, making money to bring back to his family.

That hard-earned cash proved that people like me were not helpless or powerless," he wrote.

As a teenager, Quinones-Hinojosa thought he would become an elementary school teacher. Despite his excellent grades at a teacher-training college, however, he was assigned a position in a remote, rural area; only politically-connected, wealthy kids got jobs in cities, he wrote. Quinones-Hinojosa's salary would be paltry.

His uncle agreed to let him work a short stint again at the California ranch to supplement his income, as doubts began to accumulate about his future as a teacher. A plan began to form in his mind.

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Passage into the United States

Quinones-Hinojosa had $65 in his pocket when, the day before his 19th birthday in 1987, he decided to cross into the United States for a longer stay. He wasn't thinking about laws, he just wanted to escape poverty so that he could go back and feed his family, he says.

Risking arrest, deportation and even death, Quinones-Hinojosa had a plan: He would cross the border in a "Spider-man climb" up an 18-foot-fence, hop over the barbed wire and make a leap into California, he wrote.

Just when he made it across, border agents picked him up and sent him back to Mexico.