When you begin writing, usually it's in a very simple way and everything you write within the first few years of writing is the same. This is alright if you don't ever plan on going anywhere with your writing, but if you want to write for the New York Times or write a best-seller, then you need to try something new.
Now, there are about a billion ways of writing and if you read a lot, you've probably read so many different ways that it makes your head spin. All of these ways of writing probably didn't just magically happen when the writer put pen to paper. I'll bet you that it took them years of trying out new ways to write before they came up with the best for them.
Maybe you write first person and use very simple, common, everyday words. Well, why not push yourself and try something new? How about third person, using synonyms for some of your favorite words and stretching your vocabulary. Try not to use the words 'that' and 'it' so often. Maybe even write a genre that you've never even thought about writing before.
All of these things can help you grow as a writer. Even if you decide to stick with first person narrative, your writing style will not be the same as it was before. By exploring new ways of writing and thinking, you're expanding your creativity and improving the way that you write.
Just try pushing yourself and trying something new, because if you just continue writing the same way, how are you bettering yourself?