Drawing within the lines

I don’t know why but yesterday I started to remember some memories when I was a child. I was around ten years old, I loved to draw dinosaurs. And I was obsessed with them, making sketches the whole day. Until afterwards, I notice something interesting about it.
One day, one kid, a couple of years older than me, told me that I should paint within the lines of the main layout, because my sketch was a mess.
I didn’t realize this before but, since that moment, the way I drew changed. I was quite good, everybody told me that. Basically, what I did was copying some images and drawing them.
Even the draws were good, in the end it didn’t matter. They weren’t my creations, just merely copies, however. If I had followed my style, the draws would have been mine. What if I decided to keep my style in that moment what would have happened?
What if you are drawing within the lines? Are you creating remarkable stuff or just copying someone else’s work?