This is Optimizer , a weekly newsletter sent from Verge senior reviewer Victoria Song that dissects and discusses the latest gizmos and potions that swear they’re going to change your life. Opt in for Optimizer here . On TikTok, the tanned youths are explaining why they no longer wear sunscreen. In one video, a young man films himself in the ocean while describing how you can naturally build up a “solar callus” or sun tolerance to getting burned. ( You can’t .) In another, a young woman