Just because someone else is older than you, or has won awards, or is a bestseller, doesn't mean that their stories deserve to be told more than yours do.
You are the product of years upon years of life experience that is totally unique to you. Even if someone else had a totally identical upbringing, they wouldn't process information in the same way you do. There's this marvellous thing about your brain: there isn't another one exactly like yours in existence. (And the technology doesn't exist yet for us to effectively clone you, I don't think. I'll let you know if this changes. I'll get another Steph to write for me.)
Your viewpoint is entirely your own. The ideas and opinions you formulate cannot be truly known by any other human being unless you communicate these ideas to them. Can you see how important your stories are? There are decades of writing fodder percolating in your brain, lying in wait for the day you need it. Whether you use that for essays or memoirs or poetry or short stories doesn't matter. Your words have value.
Oddly, it's the people who are told their opinions aren't valid who we really ought to be encouraging to express themselves. I don't think there's enough Young Adult fiction that reflects genuine teenage experience in this country. I don't think there's enough YA that reflects what it's like growing up as someone who follows a non-dominant religion in this country, or as someone who was born elsewhere, or as someone living with disability or mental illness, or as someone who is not only dealing with all the standard teenage identity issues but also their multi-racial identity. I think we hear too much about minority groups and not enough voice is given to the actual people. Do you not think that fiction is a brilliant way to explore other people's viewpoints? Don't you owe it to the world to share your stories?
If you want to write, you should. Your words, your opinions, your thoughts, your stories - they are important. Don't let anyone tell you otherwise. Lacking technical skill, or being too young are rubbish excuses. Your words have the power to inspire others, to entertain, to inform, to allow you to connect. Which, you know, I've got this theory that's what human life is all about. I'm still working on this theory, but don't you think it's a nice one?
You can have respect for the writing of others, for your elders, for the tradition of storytelling, and you can also have enough respect for yourself to know that your stories deserve to be told.
Listen, listen: I'm telling you the truth. You matter. Your stories matter.