Tomorrow marks the 21st anniversary of the publication of the first Harry Potter book in the U.K., yet author J.K. Rowling still seems to get surprised and humbled by how much success she’s had over the years.

Earlier this week, while exploring a second-hand bookstore, Rowling found a section labeled “Books you need to buy so you can say ‘I should read that next’ before re-reading Harry Potter,” which she found surprising.

Following Rowling’s tweet was an outpour of fan replies which further emphasized how amazing her writing is. They flooded Rowling's feed with supportive words about the ​series and her writing. Some fans shared their favorite books (which a few were re-reading, despite the bookstore sign), while others shared photos of house remodels and tattoos designed in Harry Potter fashion.

According to MamaMia, one fan replied, “Surely by now you know we’re still madly in love with your books. They’re a part of who we are.”

So far, Rowling’s tweet has gotten over 1,400 replies, 14,000 retweets and 133,000 likes. Needless to say, once a Potterhead, always a Potterhead.