We currently live in a world where the worries of an average 18yo might range from taking a perfect selfie to trying to get as many FB likes as s/he wants. Our capabilities and endowment have been played down to the lowest level, even from birth,for example, we would say "tiskit" to a 2yo rather than "would you like to have a biscuit?’’ because we think that is too complex for them to understand, you should find out how many words a 2yo can say, but that’s by the way. Now we are scared of responsibilities and still think we are kids, we are an utter disgrace to our primogenitors.
Queen Christina of Sweden, 18, ended a 30 year war and also prevented an intending civil war. Augustus Octavius Caesar, led an army to victory at age 18 and so many more, ask yourself, "do I compare to any of those’’, "am I even trying’’. "but wait’’, "that was a totally different world then’’, "things have changed" , yeah right, I almost forgot, our skill at making excuses are at its finest.
Flavia bujor wrote "the prophecy of the stones’’ at age 12 and has sold more than 20,000 copies and has been translated to 23 languages, and Juliet Beni had a Ph.d in psychology at age 19, yep, these people are from our generation. When I got admission into the university, few months after I clocked 16, my level adviser was so surprised, he said I was too young for the system, and if not I was already 16, he would have sent me back home, and I thought to myself, and Juliet Beni has a doctorate degree, and someone is here trying to stop me from getting a Bsc., the point I’m trying to make is that this essay isn’t just to my peers, but to everyone who has this sought of backward mind set.
Heck, you don’t need to be super smart, Malala Yousalzai, youngest recipient of a Nobel peace prize, at the age of 18 campaigned against the Taliban’s efforts to stop girls from schooling, Mary Grace Henry, 12-14, makes thousands of headbands to help girls in Kenya, school, and has helped more than 60 so far, and Yash Gupta, 14, who collects used glasses and donates them because he remembers how hard it was for him to carry out his daily life when he lost his glasses for a day, he has donated glasses worth 100 million USD, do you have an idea how many people he has helped?, you just need to stand up for what is right and lend a helping hand, and you are already successful in your own way.
I weep for this generation, where every boy believes music is his talent, and every girl aspires to be a model, I weep for this society that has accepted internet fraud, "yahoo yahoo’’, and drug abuse as norm. I weep for the whole system where company giants would rather sponsor music than invest in education, airtel, mtn , maltina, you name them, all organize music or dancing or modelling shows, and the few who invest in education give it as little publicity has possible. I weep for this country where the best graduating student is handed a mug and the winner of a beauty pageant in an academic is awarded a brand new car. And then they ask me if an 18yo is mature enough to marry, I say an 18yo can lead this country to greatness, because there are 40yo who behave like kids doesn’t make all 18yo dumb, it’s not about the age, it’s just the sage.

Summary/conclusion
I know many might not read this because "too long’’ or "space booked’’, but what I’m saying in essence is that, 20 years is more than enough to live a long life. Today, I say to you, THE MEASURE OF A MAN’S LONGEVITY ISN’T BY THE NUMBER OF YEARS HE HAS LIVED BUT BY THE THINGS HE HAS ACHIEVED WHILE HE’S ALIVE. You might feel this is too harsh, but it's just the painful truth.

Honourable mentions:
Anoyara Khatan, 18,
Victim of child trafficking, campaigned against children trafficking at age 13.
Thomas Suarez, Adora Svitak, Sirens Huang
All are TED talk speakers