It's true: Age ain't nothing but a number. Events in 2014 made that especially clear, as young students, protesters, artists, athletes and others created change and guided international conversation. None of them have turned 30 yet, but they're forces to reckon with as 2015 approaches. Here are just a few of the youth who changed the world this year:

Malala Yousafzai, age 17

Malala Malala Yousafzai, 17, won the Nobel Peace Prize with Kailash Satyarthi this year. Photo: Reuters

In October, Malala became the youngest Nobel Peace Prize winner ever. She, along with Kailash Satyarthi, was recognized for her efforts in securing education for all children, especially girls. Malala has been in the news since she blogged in 2009 for BBC. Eleven-year-old Malala wrote about her experiences in Pakistan, where Taliban extremists forbade girls from attending school. In 2012, the group tried to kill her -- a Taliban member shot her in the head -- but she survived and continued with advocacy work for oppressed children.

"I'm here to stand up for their rights, to raise their voice," CNN reported she said this month. "It is not time to pity them. It is time to take action, so it becomes the last time ... that we see a child deprived of education."

"Jackie," age 20

The University of Virginia student's account of her 2012 gang-rape at a fraternity house shed light on campus sexual assault issues, regardless of its accuracy. A Rolling Stone article focusing on Jackie's story -- which has been called into question -- sparked national conversation about colleges' mishandling of sexual assault, media ethics and how rape survivors are treated.

Nina Pham, age 26

Pham, a nurse who cared for late Ebola patient Thomas Duncan at Texas Health Presbyterian Hospital in Dallas, contracted the deadly disease herself in October. After being treated in Texas and at the National Institutes of Health Clinical Center, she was cured and reunited with her dog. Pham's case, as well as that of New York City Ebola patient Craig Spencer, highlighted the international need to support medical workers in contact with Ebola patients.

Michael Brown, age 18

Michael Michael Brown, 18, appears in a graduation photo attached to a protester's sign in November. Photo: Reuters

Hundreds of thousands of people protested this year the death of Brown, an unarmed black 18-year-old fatally shot by white police officer Darren Wilson in Ferguson, Missouri. The incident sparked initial protests over police brutality, excessive force and race relations in August. Discontent surged nationwide in November when a grand jury declined to indict Wilson for Brown's death. 

“Everything happen for a reason,” Brown posted on Facebook the night before his death,  the New York Times reported. “Just start putting 2 n 2 together. You’ll see it.”

Nigerian schoolgirls, ages 16 to 18

When #bringbackourgirls made the rounds on Twitter and Facebook this spring, the movement gained support from people like first lady Michelle Obama, actress Anne Hathaway and socialite Kim Kardashian. Behind the hashtag was the abduction of 276 female students in Nigeria by Boko Haram, an Islamic extremist group. Boko Haram members broke into a school the night of April 14 and took the girls, who they believe should not be educated, away in trucks. The schoolgirls' kidnapping brought human trafficking and forced marriage into the spotlight. Celebrity involvement raised further awareness about the issue, CBS News reported.

Joshua Wong, age 18

Wong Joshua Wong, 18, delivers a speech outside the offices of Hong Kong's chief executive in October. Photo: Reuters

Wong didn't want to be a symbol of rebellion. He simply wanted democracy in Hong Kong. But when China announced it stood by Hong Kong's reforms restricting the 2017 elections, Wong helped launch the Umbrella Movement advocating for democratic elections. He led protests, was arrested in September after storming the government's headquarters and went on a five-day hunger strike to push for universal suffrage.

“The future will not be decided by adults,” Wong told Time magazine. “I would like to ask adults, people with capital and power, why are they not fighting for democracy?”

Mexican missing students, average age 20

Missing Protesters have pinned their demonstrations against Mexico's drug war on the case of the 43 students missing since Sept. 26. Photo: Reuters

The September disappearance of 43 young men from Iguala, Guerrero, was the breaking point for thousands of Mexicans frustrated with the ongoing drug war. The Iguala mayor is thought to have turned the students, who were on their way to protest a speech by his wife, over to corrupt local police. After a shootout, the police reportedly gave the students to drug cartel Guerreros Unidos to be murdered.

Protesters accuse the government of not working hard or fast enough to find the students and not being transparent in its investigation. Demonstrators point to the 43 missing students as another example of President Enrique Peña Nieto's tolerance for organized crime and insufficient efforts to keep Mexican citizens safe. Since the war on drugs began in 2006, more than 100,000 people have been killed, Al Jazeera reported. About 20,000 have gone missing.

Mo'ne Davis, age 13

Pitcher Mo'ne was the 18th girl ever to play in the Little League World Series in August. Then she threw a shutout and became the first Little League player to be featured on Sports Illustrated's cover, breaking gender, age and race barriers. "A girl on the cover of Sports Illustrated for her prowess in a man's sport," TV host Deborah Norville told CNN. "Mo'ne is wowing not just the sports world but all of us!"

Taylor Swift, age 25

Taylor Taylor Swift, 25, crossed from country to pop music this year -- and did a lot more. Photo: Reuters

Swift undeniably dominated 2014. She was named Billboard's Woman of the Year, successfully departed from country music, sold 2 million copies of her album "1989," declared herself a feminist and pulled her songs from Spotify, among other achievements. Her latest record was lauded for its new sound and diverse themes -- no longer sadly singing about lost loves, Swift challenged media stereotypes and asserted her independence. She banded with gal pals Lorde and Selena Gomez and threw a birthday party attended by Beyonce. In short: She grew up and shook it off.