At 10 years old, Marley Dias noticed a problem. She loved to read, but hardly ever came across  protagonists who looked like her. So she decided to do something about it. In November of 2015 Dias launched the #1000BlackGirlBooks campaign to raise awareness about the lack of black girl characters and inspire young people to take action.

Now “12-and-a-half,” Dias is continuing her mission as the author of an upcoming book about activism. We caught up with her at WE Day, a summit and celebration of the United Nations’ WE Movement, where she addressed an audience of hundreds of young people about how young people can embrace activism.

MTV News: You started #1000BlackGirlBooks back in 2015. What are some of the biggest lessons you’ve learned over the past couple years?

Marley Dias: I stopped worrying about being the best and started doing my best. Instead of focusing on what my friends wanted to do or what the most popular kids in school wanted me to do or what my mom wanted me to do, I started focusing on what I wanted to do. I began focusing within and getting my energy from what I wanted to do and what I aspired to be.

I think kids should think about what they personally want rather than basing their goals around other people. We don’t know everyone’s lives, we don’t know everyone’s experiences. We don’t know why they set their goals, we don’t know how they come to their ideas. I think selfishness and being jealous is never good and can never help you create social change, because you become so focused on not actually helping a person and creating impact, but on being better than another person, which is completely what social change and activism is against.

Do you think anything about the campaign itself or your mission has changed since you started?

Now that I’m 12 — I’m going to be 13 soon and I’m very excited about that — I think that I’m able to connect with more people. When I was in elementary school, I didn’t really experience drama, it wasn’t part of my life. But now that I’ve grown up, and am closer to being a teenager, I experience more problems like anxiety, bickering with my parents — every kid does — and a lot of kids at my school [deal with] body image and self esteem. I didn’t really think about those things when I was 10, but now those problems are more present and I think about them more.

Have do you think your age has affected what you’ve done and how it’s perceived?

A lot of the time it’s very hard to get my message across because of my age. I’ve done a couple interviews where I felt like people were paying less attention to what I was doing and paying more attention to the fact that I was 12. But as I’ve learned through the campaign, I’m not the only 12-year-old who makes social change. I might be the only 12-year-old who was on Charlie Rose talking about it, but I still think my cause is equally as important as [those of] every other kid who wants to make a change.

[But while my age] doesn’t define what I do, it does shape it. I understand that because I’m 12 I face different issues than a 30-year-old woman does, but I also don’t think it should define how much people should take me seriously. When I go into a meeting and try to explain my idea, people are like “you’re so cute,” “you have such a great smile,” “you’re so tall for a 12-year-old.” I don’t want that to be the main reason why you’re listening to me. I want you to focus on my content. But I also think you need to understand that my content is shaped by my age. Your age is important, but you don’t want it to define you and it’s very difficult to explain that sometimes.

What do you think adults misunderstand about people your age — especially young activists?

Not to generalize, but I think a lot of adults … don’t think about how we live in a different world [than they did, and] value things they didn’t care about [when they were growing up]. Social media didn’t exist when my parents were born, but it’s a huge part of my life — not because I’m self-obsessed or vain, but because that’s how I get the message out about the things I do. A lot of the time, adults need to respect kids in that sense. They can monitor them, but they need to let them make mistakes sometimes because that allows them to learn. As my mom says, never make the same mistake twice, but still make a couple so you learn how to actually use that and share what you learn with other people.

When did you start to identify as an activist and what does it mean to you?

To me, an activist is a person who sets a goal for their local or global community to uplift them and exceeds or reaches that goal to the best of their ability. I think the media often considers an activist to be someone who is making a change on a big scale with flashy cameras, expensive equipment, hair stylists, makeup artists, publicists. But activists are really the people who are setting goals for their community and helping one another and using their resources to reach those goals and exceed those goals.

What are your conversations with other young activists like? No matter what you fight for, do you think you generally share common concerns?

My topic, diversity in children’s books, is very specific, but diversity in general is a very, very big issue … Diversity always comes up because there’s so much difference in the world and that’s [not always] embraced through big platforms so much. I’m a black girl and I want to be on stage … to talk to big audiences. A lot of the time, [young activists] wish there were more diverse audiences and more diverse people working with us so that we think about what we do and what we say in a way that includes everyone.

You recently announced that Scholastic is publishing a book you wrote about activism: Marley Dias Gets It Done: And So Can You! Tell us about it.

Marley Dias Gets It Done: And So Can You! Is a practical guide for teenagers and kids to blend their gifts and talents and dreams with campaigns they want to start about issues they see. So if you love soccer [the book will help show you] how you can blend that with [an issue] that’s applicable to other people. The book [helps] connect those pieces so you’re able to make something, to create a perfect formula of how to create social change while doing what you love. I try to always tell people to take your passions and blend them [with activism].

What advice do you have for young people who want to become activists but don’t know where to start?

The best place to start is social media. I didn’t know that so many other girls, so many other people, were doing things until I looked at my phone and I saw my explore page and saw for example that there were a lot of kids in Tokyo who also saw a lack of diversity [in media].

Also, use social media responsibly. My rule for kids my age is basically don’t post anything you wouldn’t want your grandma to see. It makes sense for me — my grandma would not appreciate if I posted anything inappropriate. Social media is a great tool.

For more information about #1000BlackGirlBooks, visit www.grassrootscommunityfoundation.org. You can follow Marley on Instagram @iammarleydias and pre-order her book here.