A new report in The Wall Street Journal highlights comments by Apple’s chief designer, Jony Ive, on the challenges of designing the Apple Watch. Speaking at the San Francisco Museum of Modern Art on Thursday, Ive explained that although he believes with “every bone in his body” that the Apple Watch will break new ground in computing devices, actually designing it was more challenging than the iPhone due to the “social expectations around a wristwatch.” Ive noted that the wrist is an ideal place for “lightweight interactions” and “casual glancing” but not for heavy reading. He went on to explain that there are “cultural, historical implications and expectations” around designing a watch, and described it as a “humbling” experience, stating that creating a wearable device raises new consumer expectations that had to be addressed, such as a wider selection of cosmetic options as people don’t generally all wear the same thing—except in prison. Ive also stated that his focus is entirely on creating great products, rather than paying attention to Apple’s finances, and revealed that he doesn’t even know sales and revenue numbers, other than that “they are high.”