It’s not that LEGO “grew up.” Better: it learned how to package therapy, nostalgia, and display status, and sell it in a box. Trot through a toy aisle today and you’ll see strange things indeed. A LEGO bonsai tree. A bouquet of plastic flowers. Maybe a 9,000-piece model of the Titanic. None of these “toys” are designed for kids. They’re all made for big’uns. Seriously, the toy industry calls these buyers “kidults,” and they’ve managed to become one of the fastest-growing segments in toys. I’m...