I first picked up my (first) copy of Jane Eyre when I was around ten. I was browsing the Barnes & Noble children's classics and thought the cover, the mysterious plot summary on the back, and the hints at Charlotte's dark/sad early life influencing the book all looked rather interesting. I couldn't at the time put a name to what was drawing me in: the Gothic.
It wasn't until a year or two later than I actually got through reading the book (I had started it, but been unable to continue). I read Emily's Wuthering Heights not long after, and followed about a year later with Charlotte's Villette. Within the next three years, I had also read her Shirley and Anne's Agnes Grey. Sometime around my first year of college, I finally got to Charlotte's The Professor and somewhere in there I also read two of her novellas written in her teens. I may have thought something along the lines of, oh, I've read all her books now, all Emily's, and have only one left of Anne's (The Tenant of Wildfell Hall, which has been sitting waiting on my bookshelf for years).
I'm only beginning to grasp the vastness of Brontë material that's out there. I picked up a copy of the sisters' poems at the school library and I've been reading a couple a day. While some you could call simple, others are quite good, especially Emily's. And I have a copy of Charlotte's Tales of Angria--and there are plenty of Angrian tales not in that volume. While Angria was the fantasy world Charlotte and her brother Branwell wrote about, Emily and Anne wrote about Gondal--so there are the Gondal stories, also. Then there are the handy copies Selected Letters of Charlotte Brontë and The Belgian Essays. Some of this material is relatively new to publication. What may seem like material just for scholars is available to everyone.
Just think about the amazingness of that. With a few clicks online, you can have pages and pages of Brontë material at your disposal. The seven novels are just the start. These sisters wrote. A lot. So to only read their novels (especially to only read Wuthering Heights and Jane Eyre) is to ignore all the rest of what's out there. It's like a Tolkien fanatic only reading The Lord of the Rings (okay, I don't know that the Brontës had as many piles of notes as Tolkien did, but who does?)