We are at learning stage. A lot of mistakes happen on daily basis. But we should learn from mistakes. 
As saying of a person 
"to do mistake is not called mistake 
But to repeat mistake is called a mistake".

Before doing a deal with someone we should be aware from advantages and disadvantages. 
The results could varry from our thinking.

Thanks @chbartist , you really are a caring person. Keep on posting such contents to educate folks