The thing is, your fantasy sort of begins in the middle - it doesn't include the extremely difficult start-up phase. It doesn't include up to a year of little-to-no income, working 16-hour days, or appeasing difficult clients because you just can't afford to let one go.
Are you willing to double the hours you work? Are you willing to make the tough calls and deal with the consequences when there's no good answer? Are you okay with paying your creditors and employees first when it means you may not take home a paycheck that month?
Do you have enough savings to start the business, and pay your bills for up to a year? Will your spouse resent the extra burden of maintaining the home, family and income while you toil away at launching your business? These are vital questions - poor planning causes businesses - and marriages - to fail before any kind of stability is achieved.
Know Your Talents
Most people start a business based on something they happen to be good at - but make sure you're really, really good. Good enough, in fact, that people will pay you to what you do. Your mom may love your cupcakes, but how will they go over with total strangers who are paying $4.00 each for them? Whatever it is you do, make sure you do it perfectly.
There is an entire class of entrepreneurs whose talent is starting businesses. Some specialize in a general field, but others take all comers - these people are very good at spotting trends and people with the talent to bring them to market. Once the business is solvent, they sell it for a nice profit and move on to the next project.
Building toothpick houses may be fun, and you may be the best toothpick carpenter around - but the demand for toothpick cabins is low. Perhaps you could apply your skills to general model making and market yourself to architects and designers, who pay top dollar for 3D representations of their designs.
Musicians are a dime a dozen, but very few make a living wage by playing music, so many give lessons. The market for great moms likely only extends to your kids - try opening a daycare to spread your skills around. Look for a way to present your talent that will make people think they cannot live without it.
Do Your Homework
You've identified your talent and your product, now you must make sure it's feasible where you are.
Say you want to open a Mexican restaurant, but a quick Internet search shows that there are already a dozen Mexican restaurants in town - you're almost sunk right out of the gate, because competing with already-established businesses that are so similar can easily kill a struggling start-up.
Do another Internet search - are there any good steakhouses? Seafood restaurants? What about bakeries? By shifting your focus slightly to one side, you've drastically reduced your competition and increased your chance of success.
Once all this is finished, congratulations - you've taken your very first step in learning how to open a business. Now go find a building, design stationery and a website, write employee handbooks and job descriptions, create your business plan, find financing, hash out an advertising budget and get to work.