I want to have two ways I develop my life: The one part where I focus on my current project, and the other where I can explore anything.
Focusing on your project means that what you create is done with a specific goal in mind, like bringing value through your product, or through your teachings, without deviating too far from the main topic. This is necessary if you want to reach out to your audience and be useful to them.
Exploration is a way to open your mind further, think about new topics, make new friends on the way. It will help you find new project ideas, and make connections that would help you differentiate your project from others.
A healthy dose of both those ways of working seem like a good way to make progress, as they would build on each other.