usdjpy selling

How to understand the phrase "the simpler the trading system, the better"?

What is the degree of simplicity here? Or the simplicity here is not what I thought, just use a few indicators, so what do you think of this sentence?

For the real-time market, should we keep our original intention or follow the trend?

Are you happy doing business?

There is no such question, so I mention it.

Where should beginners start trading?

Tell me how hard you have worked to make money in trading?