A marvelous mental exercise is to contemplate the basic things in life we all take for granted, things so interwoven in the fabric of our daily existence that we hardly ever notice. Why are they the way they are? What if they didn't exist, or were different? What would a Martian observe? What might puzzle or amuse him? How might things be different in a science fiction alien existence?
Thinking about such things is fundamentally educational, making us much more aware of what makes life the way it is, what things are important, what has to be considered when planning to do anything, what alternatives are conceivable and possible, and so on. It's also a basic exercise in thinking and observing, forcing us to notice things too familiar to see. And it stimulates the imagination.
A person should be able to write a good-sized essay about every one of the following topics. Another challenge is to extend the list, forcing ourselves to notice what else we might not have noticed till now. Another is to see how many facets there are to each topic, avoiding the rut of any single view. And another: what are the similarities and differences among these topics? Would you group them differently?
As with any sizeable list, there's a danger of getting numbed by the sheer volume of it all, bouncing mechanically from one point to the next to the next... To get the most out of it, after skimming to get the idea, take one idea at a time and think about it all by itself. Maybe pick one to dwell on for a day, coming back to this list as a resource whenever you'd like to think about something new.
Remember, you can raise at least the following sorts of questions about each thing in the list:
A starter list...
What can you do with this list? Think, discuss, investigate, write, teach- more or less in that order. Don't go and read about these things just yet. Even if I eventually add some essays on these topics, don't read them yet. Stretch your own mind and imagination, see what you can come up with on your own. What is it? How did it get that way? Why is it the way it is? What if it wasn't? That's an essential ingredient of creativity, both artistic and scientific: being aware of what there is, articulating the underlying assumptions we always take for granted, and imagining that things might be different.
How many different aspects or sub-topics can you think of? After you've thought about a topic for a while, see if you can't come up with a totally different side of the same topic.
What connections are there among these topics? Notice how often the others crop up when you're thinking about one of them. Then try taking any two of them whatsoever and forming some sort of relationship. See if that works taking groups of three or more.
Regroup them in various ways. How would you think about them differently if they were clustered differently?
Try extending the list. I had a certain criterion in mind, which isn't always exactly clear or sharp. It's not just a list of interesting topics. You can get that from any encyclopedia or library catalog. The focus is mostly on things we take for granted, mundane things that occur so naturally in our lives that we forget to notice, or wonder about them.
Then talk about these things. You'll learn a lot about these topics, and about people as well. See how different people react to the list in general, and to specific topics. Some will be stimulated, some will be bored. ("Dirt? Why do you want to talk about dirt? Dirt is dirt. Don't waste my time.") You might also think about your own reactions. Are you stimulated or bored? How do you feel about discussing these things? Why?
Pretty soon you'll be ready to dig deeper. Start reading, after you've given your own mind a chance to explore freely without being pre-channeled into certain points of view. Check the encyclopedias and other resources. How many aspects did you think of by yourself? How many new ones did they know about? Did you think of something they didn't?
You can write about these things, too. You might do it for yourself,as an exercise in organization and communication. The ideas don't have to be original. And you can awaken other minds to these things, especially children's minds if you're a parent or teacher.