Ask HN: How do you make sense of the economy

I'm often struck by the sheer number and variety of companies and jobs that exist in the economy. I can often go through the list of businesses in an office park and find something I had no idea was a business, ex., fabricator of plastic grocery store displays. Obviously someone has to make them but I would never think of that as a business. I contrast this with the seeming lack of business opportunities I come up with. I know that this lack of opportunities is just an illusion caused by my narrow experience, so how can I overcome this? I try to take advantage of interactions with random people to find out what they do but I'm wondering if there is something more systematic I could do?