Johanna Basford's intricate hand-drawn coloring books for adults have sold nearly 1.5 million copies worldwide. Courtesy of Johanna Basford/Laurence King Adulthood seems to be having a regressive ...

Well, at least it's not Fifty Shades of Grey. The two top-selling books on Amazon.com right now are Johanna Basford's Secret Garden and Enchanted Forest. Sounds unremarkable enough, right? Could be ...