Why do investors either lose money consistently, or make money and then give it all back? The answer is simple: if the method is wrong, how could the result be right?
So stop, and ask yourself honestly: from the first day you started investing until today, are you up or down?
If you are up — can you sustain a return above 10% a year for five, ten, even twenty consecutive years? If you can, congratulations: you could write a book about investing, and you can stop reading here, because the rest will only waste your time.
If you cannot, the problem becomes much simpler. Two things are certain. First, the method you figured out on your own does not work. Second, the methods you got from other people — whether heard second-hand or paid for — do not work either. Why? Because if they worked, your pocket would already hold what you want it to hold. If it does not, some things deserve to be thrown away.
Once you find the reasons you lose money, or fail to keep it, most of the investing problem is solved. Investing exists to make money, and the way to make it is to find one simple method that has been tested by practice. That method is what Warren Buffett calls value investing. Why is value investing simple and effective? That is a topic for another day.