The definition of "Young" is: "having lived or existed for only a short time". This is the most simplistic and vague form to describe what being young really means. You probably spent most of your youth trying to be older, or growing up. Looking up to those who were driving, with the freedom you so desperately wanted to have. Persuading everyone by acting like you have some clue of what being mature really is. So why is it important that you go through it?
Because that's not how you should spend being young.
When you're young, like the definition, you've only been here so long. Your eyes have only seen so much, your heart only goes through so many of a number of emotions. Your brain can only know so much, and your feet have only walked so many steps. There are the awkward phases and terrible hormones, with pimples and peer pressure.
The disadvantages aside, you have so much to live for, including dreams to be reached and goals to be met. That doesn't mean you can't make many mistakes on the way. You won't be around the same people forever, and to the ones that you do, cherish them throughout. You'll fall in and out of love and back through, with the people who make you laugh loudly and cry softly. You'll wonder why things happen and where is the next step to change them. You'll grow up with people who you never see after high school. You'll meet mentors and teachers who will impact the rest of your life. You'll find friends, some only there for a moment and others for your lifetime. You'll realize they weren't kidding when they said that family is the most important. You realize everything about the world and how it works, the ups and downs. Your thoughts and tastes about things and even people will change as time goes on.
And you might not know it now, but there will be a point where you reflect on everything you did in your youth. The family, friends, good times and bad. But try not to think about regrets, and actually do what makes you happy, because in the end, that's all that matters. Not the bad grade on your paper, or that party you had to miss. After years all that counts is what you came out with, and of course, all the memories that follow. Being young is the best part of life because you get endless chances to find yourself and who you are.
So stop asking to be older, and waiting for your next birthday, and saying it's not fair that you can't do something because of your age. Because one day, you'll turn around, and just like all what you've heard from the people before, and say "Oh, what I would do to be young again".