Born in Maturin, Venezuela. The family lived at the oil camp in Morichal until Jhonattan was around 12 years old. There was a nearby nine-hole course built for the employees where the family could play golf. The family relocated a couple hours north to another oil camp in Quiriquire around the time Jhonattan was 12 years old. The nine-hole course there was challenging and hilly, and there were a group of juniors who formed a strong bond with one another through golf.

Upon graduating from the Korn Ferry Tour at the end of the 2010 season, became the first player from Venezuela to earn PGA TOUR membership. In his second start as a TOUR member, became first Venezuelan to win on TOUR with his victory at the 2011 American Express.

Franci Betancourt, a former pro who represented Venezuela three times at the World Cup of Golf (1966, 1968, 1975), served as a mentor for Jhonattan upon moving to the United States. Betancourt previously taught golf to children in the Venezuela oil camps until he relocated to Houston in 2000.

Picked up the game by playing with a broomstick and a rock.

Is a scuba diving enthusiast. Loves to explore the ocean and "see a whole different world." Had a particularly memorable dive in Mexico when a bull shark swam right up to his group.

Was a standout third baseman as a junior baseball player.

Within less than a year of relocating to the United States, Jhonattan successfully open qualified for the 2003 Texas Children's Houston Open and made his PGA TOUR debut as an 18-year-old amateur.

Played four seasons at University of Texas (2003-07) and graduated with a degree in kinesiology.

Reached the semifinals of the 2007 U.S. Amateur Championship, contested at The Olympic Club, and was eliminated by Colt Knost, who went on to win the title. Vegas notably defeated future PGA TOUR winner C.T. Pan in the quarterfinals.