Designing a great logo is about more than just choosing a typeface, adding a few colors and an on-theme icon. A logo is the first impression a company makes on potential customers—a touch point that represents everything a company is trying to convey. It affects how people perceive and interact with a brand, and ultimately becomes the brand’s key identifier.

While designing an attention-grabbing logo is difficult enough, redesigning a famous logo brings with it a whole new set of potential issues. When Gap changed their 20 year old logo back in 2010, the customer outrage was so fierce, the new logo only lasted a week. Instagram’s new logo has grown on most of us, but when the image sharing app unveiled its new look in May 2016, the design was described by one Guardian writer as, “if the camera was murder, and chalk was drawn around its body. Murdered at sundown.”

Many brands have embarked on the perilous journey of redesigning their logos, and while not all are met with outrage, many have hidden meanings or hard-to-believe backstories. We’ve rounded up 10 logo design secrets from famous brands that shed light on the mysteries of designing—and redesigning—logos.