Can you please tell me what this means. I don't understand it thank you.

I had never quite understood the dividing line between not growing up and being grown up. It seemed as though there was some invisible doorway a person walked through and when he came out on the other side he was suppose to be all that he had been before, except more.

its talking about not quite understanding maturity in which a young person grows up to become an adult. for some its like watking through a doorway and for others it seems they can't even get the door open.

The person is confused as to what being "grown up" really means.

The passage you provided is a quote that expresses the confusion and ambiguity surrounding the transition from childhood to adulthood. The writer mentions that they have struggled to comprehend the line that separates not growing up and being grown up. To understand this quote better, we can analyze the text.

The writer mentions an "invisible doorway" that people are supposed to walk through. This symbolizes the transition from one stage of life to another. When one goes through this doorway, they are expected to retain their previous characteristics but also possess newfound maturity and development. In other words, they are meant to be all that they were before, but with additional qualities that come with adulthood.

Understanding literary quotes like this involves interpreting the author's intended meaning. In this case, the author is reflecting on their own confusion and uncertainty about the process of growing up and what it means to be an adult.