Looking on the internet deeply has found these results:

People need to understand this. is the most popular phrase on the web.

Because this needs to be understood. 10 results on the web	People need to understand this. 12,350,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	People need to understand their rights if they are to exercise them. People need to understand the seriousness of this illness! On the other hand, experts in the field advise that encouraging software protection is vital for the media industry as people need to understand the concept of property rights. People need to understand that normality does not exist. Furthermore, people need to understand the disease and adapt their behaviour accordingly therefore communication must be improved. People need to understand that interventions on nature have an impact on the economy. People need to understand this. His people need to understand that I'm not just rattling my saber.

Because this needs to be understood.

10 results on the web

People need to understand this.

12,350,000 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

People need to understand their rights if they are to exercise them.
People need to understand the seriousness of this illness!
On the other hand, experts in the field advise that encouraging software protection is vital for the media industry as people need to understand the concept of property rights.
People need to understand that normality does not exist.
Furthermore, people need to understand the disease and adapt their behaviour accordingly therefore communication must be improved.
People need to understand that interventions on nature have an impact on the economy.
People need to understand this.
His people need to understand that I'm not just rattling my saber.