Money is known to be identically exchangeable. Grocery stores will accept any dollar you pay them. How you got the money is none of their business.

However, earning the dollar can be, altogether, a different situation. A dollar you earn doing work you hate, is very different from a dollar you earn for something you love. Many people would consider earning less money, if it meant spending more time doing what they love.

Money from paychecks and consulting fees pay my living costs. The royalties from my book pale in comparison for now, in terms of size. However, the royalties are also indications that people think my writing is worth paying for. Because I wrote my book from my heart, it makes all the difference to me; the dollars are not the same.