A key part of happiness is understanding the role and nature of problem-solving in life. We are always solving problems. A problem can be defined as a conflict between ideas. The process of solving it requires the creation (and testing) of new ideas. Here are examples of problems: how do I relieve this back pain? how do we enable knowledge workers to collaborate more effectively? how do we reduce poverty? how do we resolve the incompatibility between quantum physics and general relativity?