The term Multiple Streams of Income in a way voices and explains itself. It’s the theory of earning more than one type of income from more than one source. Generating multiple sources of income is a key to wealth creation, it becomes even more special when you’re doing it with a passive income which does not really require a lot of time and efforts from you (We’ll talk more about that later).
I’m looking at accepting a professor job. It’ll be more than a 50% pay cut. But I’ll have the same life you describe – endless summers and an entire month every winter to ski. I’m thinking in the end, eventually, I might even end up wealthier in more ways than one. Happy people tend to be the most successful. I have no desire to diversify. Dividend stocks allude me. CDs seem like a good choice for older people, but I have time on my hands and real estate knowledge, so I’m sticking with what I know, despite the fact that most people will tell me it is foolish and I should diversify.

4. Calculate how much passive income you need. It's important to have a passive-income goal — otherwise, it's very easy to lose motivation. A good goal is to try to generate enough passive income to cover basic living expenses such as food, shelter, transportation, and clothing. If your annual expense number is $30,000, divide that figure by your expected rate of return to see how much capital you need to save. Unfortunately, you've got to then multiply the capital amount by 1.25 to 1.5 to account for taxes.
For a person working for a wage, their source of income is their job, or their labor (aka their time that they sell to someone). But you can own a house, and rent it out, and when your renters pay you renter every month, the source of that income check is your rental property, or your house. It would just be called rental income. If you have money in the bank in an account that pays interest, those interest payments are another source of income. We can say the source is interest payments, or we can identify the asset that is generating rent, and say your money in the bank that is generating “rent” (aka interest) is your source of income.