One of the fastest and most reliable ways to get rich is to hit people on the head with a club and take their valuables. This is a historically proven method which has worked many times in the past.
The upside is that if you are not satisfied with the amount of riches you own, you can repeat this process as many times as you want. You can even pay others to do the clubbing for you.
The requirements are simple: a strong arm, an endurant stomach, and a flexible sense of ethics.
The greatest downside to this straightforward method is the big risk: people can hit back. You might get rich fast, but if you are not careful you might not be around long enough to enjoy your wealth.
Unfortunately for proponents of getting rich fast, this method has even greater risks in modern society where the common thug is at a disadvantage. (Still, there are many places in the world where this method continues to work reliably.)
For most of us it makes sense to sacrifice a bit of speed and find a less risky and more ethical way to get rich.