The more interesting question is:
"How do you learn entrepreneurship?"
1. From your prior experience that has given you granularity and knowledge of particular customer needs (opportunities). The majority of us start businesses based on our previous work experiences. RTMS, Inc. began when I saw an idea used for selling obstetrical equipment in 1980 (very targeted marketing) and made the connection to retail applications.
2. From the experience of others for which you have a framework. If you are fortunate to be part of a network of entrepreneurs, you can validate what they tell you against what you know. This is a very difficult task for most of us. We have all said, "Yes, but this is different." But most of the time, "it" isn't. It is a little like Indiana Jones stepping off the precipice into the abyss, based only on his trust in the directions he had recieved.
Those with more capacity to synthesize the epxerience of others go "up the learning curve" more rapidly. Good advisors are very important. Finding a way to pay close attention and validate their experience in the context of your business is a core skill for enrepreneurs working with advisors.
Cases and simulations are another way to integrate the experience of others within your own experience.
3. From the study of entrepreneurial finance. Early on, I skipped this step. The tuition I paid to learn it cost a lot more than any coursework ever would have. We don't start businesses primarily for financial reasons. We play baseball for the love of the game. But we do know how to keep score. Entrepreneurial finance is the same thing. You (the entrepreneur) have to know how score is kept. This is much more than accounting. It goes directly to what investors expect, what the benchmarks of good financial performance are for the enrepreneur's particular business, what financing alternatives to consider, etc. (Do you know what an RMA ratio is? Ask your banker!)
4. From self-awareness and personal growth. There are no mistakes in the world; only lessons that keep repeating themselves until we "get it." Great entrepreneurs examine every interaction, always looking for ways to improve, lessons to learn, ideas to synthesize and grow.
5. By believing that knowledge is power and whistling past the graveyard is a fools game. When I meet an entrepreneur who has command of market knowledge, it usually means she is going to be successful. She knows the strengths and (inevitable) weaknesses of her company and its place in the market. She can fairly assess risk; she is fully aware of what others are doing. She has a realistic handle on her costs and where the risks in the financial projections lie.
Compare this to the person with the 50-page business plan who, when asked a couple of 30,000 foot questions about others in the market, does not know. "But," they say, "it's not important. Microsoft, GE, or Gigantic Industries are so (conservative, slow, stupid) that they'll never see us coming until it's too late." They forecast EBIT three times higher than anyone in the industry has ever achieved, but can't really explain why, aside from "more efficient cost structures." Whistling past the graveyard.
So how do you teach entrepreneurship? Perhaps a place to start is laying out this framework and providing opportunities to participate in each part.