J. Michael Monahan lived his life with a lot of heart.

The 16-year-old Evanston resident died in his sleep March 18 of natural causes. His heart was twice the size of a normal person, according to reports from the Cook County medical examiner.

Family and friends were not surprised.

“(Monahan) was a great kid and he had many gifts,” said his mother, Kathy McDonald. “(His life) was short, but it was full.”

Adam Hoge, 16, a good friend and classmate, remembers Monahan as everyone’s buddy.

The two teens met when Hoge crashed Monahan’s 15th birthday party.

Hoge said Monahan gave him a “who the heck are you look” that only lasted a few seconds before they became fast friends.

Their friendship was filled with what children call adventures and parents call scrapes. The events of one summer resulted in 47 stitches between the two.

“(Monahan) did crazy things,” Hoge said. “But at the same time he knew more about life than anyone I ever met.”

Monahan was always trying to teach his friends the lessons he learned from his own experiences, Hoge said.

“Mike was always concerned with helping us get through problems we were in,” Hoge said. “Just remembering the things he would tell us … has helped us get through this tough time.”

Monahan genuinely enjoyed people and had a great sense of humor, said Rev. John Belmonte, Monahan’s advisor in the electronic media club at St. Ignatius High School, a Roman Catholic high school in Chicago.

One of Monahan’s escapades was particularly memorable to Belmonte. Monahan once bet his friends he could go through the school day barefoot. But St. Ignatius requires students to wear shoes at all times. In order to win the bet, Monahan stuck his feet into his bookbag during classes.

But McDonald said her son was more than a popular kid or jokester. He was also very focused.

Though he continuously had to be torn away from his cell phone because he was always talking to friends, Monahan hoped to go to Northwestern, become a lawyer and end up in the White House, McDonald said in her son’s eulogy.

“Even reminding him that if he was president, I would be the mother of the president didn’t dissuade him,” she said.

Family and friends remember Monahan as somewhat of a whirlwind — full of energy and always on the go.

“He teaches us the lesson that there are no guarantees, but he didn’t waste a minute,” McDonald said. “He ran full out.”

Monahan is survived by his mother; father, Joseph; brother, Colin; and sisters, Leigh and Kate.

The Daily’s Jesse Abrams-Morley contributed to this report.