What makes someone important or impactful.

During this time in my life I face peer pressure and criticism everywhere I turn. I often catch people telling me how I should be and what I not suppose to be. Its hard to find who you really are in this world when there are so many people from different backgrounds and ideas telling you how your suppose to be. People I met in my life influence me one way or another. For the good or the bad. Some individuals such as my parents have a large impact on my life as well.The question I have is what is the difference between influencing someone and having a big impact on someone.Also what does it take for someone to have enough power to impact another person.