Not only did I study every one of those 200+ pages per magazine, but I copied the photos inside with my colored pencils, india ink, and watercolor paints. I drew horses standing, walking, running, grazing, horse heads, horse hooves, whatever caught my eye. And I got good. Eventually, I started drawing them without copying photographs, and many of the details stockpiled in my mind became pretty useful.
Most of the time I went for realism like this:
But sometimes I made more simplified versions, such as this:
Whatever style directions I went in, that was the time when art went from being just something I enjoyed, to being something I enjoyed so much that I wanted to make a career of it. That time, from around 10-13 years old, was what I see as my artistic beginning.