Play

Not just in design, but play is essential in life. It's good to make mistakes as long as one learns from them. It's one of the best ways to learn. If we don't know about something, we explore. We should be curious. In terms of design, play is a way to find solutions to a problem one wouldn't get to otherwise. The Eames were known for play. They would often get inspiration from toys that they "played" with and enjoyed. That spurned into ideas for larger and more complex concepts. Instead of being rigid and looking at textbooks, one also needs to interact with their surroundings. It's a big way to learn.

http://www.eamesoffice.com/blog/five-things-charles-ray-eames-teach-us-about-play/

Examples