The question asked is "Is LEARNING the trading business like LEARNING any other business?"
Not OPERATING/MANAGING a business.
From a literal point of view, of course, it's the same. There are specific things that must be learned in order to trade or to maintain a business with success.
The learning PROCESS is different, imo. If you decide one day to go out and buy a business (Jiffy Lube, Retail Store, Restaurant, etc.), a person can do so, simply by inspecting an owner's books, watching customer traffic and arranging for complete training. You know if you are looking at a successful business. It is in front of you in black & white. If the business is already doing well when you buy it and nothing major has changed, and you don't go making any huge mistakes, chances are you'll do well too. The process is pretty straight forward. You work hard, keep things going just like the previous owner and you make money. In other words, you simply LEARN or COPY what someone else has already done to be successful in their business.
With trading the LEARNING process is completly different, at least from a retail standpoint. Unless you have an excellent mentor that lays out his evidence of success, and trains you one on one for a long time, you have no choice, but to go to the school of hard knocks. Sifting through all the bullshit requires lots of time, but it can be done.