There is always one person that we can always have total influence on. That person is youself. I can't control anyone around me, but I can always control what I do.
This personally helps me, because sometimes I get so worried about the people around me and them making the right decisions and I forget that I have my own problems that I need to take care of first.
Yes we are called to have influence on the people around us, but we have to start with ourselves first, and sometimes that is a big job.