Dear Diary,It began with the royals, and then the Derby sealed our fate. We are officially obsessed with hats.May 5: We scour the Web, city streets, even the mall, trying to find someone who can feed the fixation.May 7 (5:03 p.m.): Hope almost lost. We hear about Susan Morehead’s Suzseams, an authentic millinery shop online, right under our nose.May 7 (5:15 p.m.): Browse the collection of handcrafted, vintagey styles. Click on the seagrass cloche and a pink visca straw number. Get light-headed.May 8: We learn of Morehead’s photographer hubby, who makes the pine blocks on which she molds each timeless headpiece. Love.May 9 (11 a.m.): Make a beeline for Inman Park. Decide on the pink one. Think about where to wear it and settle on patio happy hour. Today.The Mad Glad HatterAvailable at At the Collective, 280 Elizabeth Street, Inman Park (770-696-5845 or atthecollective.com); online at suzseams.com, $50-$110.