I've wanted to be a writer for seven years and that's not showing any sign of changing. I also wanted to be a vet before, but my dream job hardly ever changed. I remember nobody took me seriously when I was 4 and said I wanted to be a writer, but I always was pretty proficient with words. Knowing and using the word proficient at age 10 is a sign of good vocabulary.
I guess others have made super long posts, so I might as well too. Here is the entire story of my wanting to be a writer (and the proof it's not just a little kid being silly!):
When I was really little, like 2 or 3, I loved talking and using the few words I knew. I always said what I was doing whenever I did something, I'm sure that was really cute. I even remember a little bit - I loved learning new words and using them. It was like my hobby at the time.
When I started learning to write (which was before I started school), I loved it. My first story was called "The Car Wash Capter 8" (supposed to be chapter 8 but I was 3 then) and it was very short and about washing a car (LOL), but it seemed like a very long story to me. Looking back, I'm amazed at the handwriting and spelling I used.
I also started using the computer at a very young age - 5 or 6. I played with Microsoft Excel and made pictures by colouring squares, like the pixel art I sometimes do nowadays. I learned to type very quickly, even though I was slow at first, so by the time I was 7 I could type about 10 words per minute. I typed a two-page story about guinea pigs and dolphins at school, but I remember it took ages because by then I was well-known in my class for good spelling, and everyone kept asking me how to spell words I saw as easy but were actually difficult for their age. I loved writing, and I remember once the teacher was writing on the whiteboard what we had to do for our English lesson; it said "write a story" and I got all excited, but then she wrote "about a monster in the park" and my heart sank. I made up a giant dolphin monster that had an oversized beak and had got stranded at the park. Unlike the other kids' stories, mine was about people rescuing a giant dolphin from a park.
This kind of thing went on through my early years at school, but when I moved to my third school in 3rd grade I noticed that school (which I'm still at now) had much less creative work and more easy things. When I started my 5th grade SATs (which I just finished yesterday) I was completely taken aback by how BORING the subjects we needed to write about were. A page-long review about a pair of trainers or a singer or how excited you are before a hot air balloon ride - impossible! There was one practice paper where we had to write a spooky story about a girl entering a shed. I completely missed out on most of the marks for "composition and effect" because I made up a sign saying "Silly Moocow Club" and chairs the right size for exactly 100 ants. Hardly spooky...
Another memorable incident happened quite recently - we had to write a story for English. A story about, for once, ANYTHING WE WANTED. I completely grabbed the opportunity and before I knew it had written 11 pages and still was not done. It was a story about living fruits attacking each other. My teacher didn't like it OF COURSE, but my friends think my writing is hilarious.
So, that's my long and far from finished description of why a writer would be the perfect future job for me!