In John 9:1-9, Jesus healed a man who was born blind. Pay attention to verse 8 where it says "8 His neighbors and those who had formerly seen him begging asked, "Isn't this the same man who used to sit and beg?" Notice how the people who REMEMBER him as a blind and begging man, do not KNOW him to be the man that Jesus healed. There is a difference between knowing someone and remembering them. God knows you, but a lot of people just remember you. 

John 1:1-9

Mark 6:4