Anbody know what a dream about somebody knocking on your door mean?

And it tripped me out because the knocks became so loud that I woke up and waited to hear it again because I thought that it was real, but in the dream, I was thinking that it may have been my sister. But I did not answer in the dream because I was not sure about who it was and wanted them to go away. Just yesterday I decided to let go of something that bothered me for six years, because it was affecting my health more and more. Could the knocks signify curiousity about new things to discover in life or something?