The imagery of Vera's young life
Brittain explains that in her home she was made to feel like a psychic prisoner to her father's unfounded beliefs about boys and girls. From the details provided, the reader should be able to put together that the father was projecting his own perceived insecurities on her, "protecting her delicate sensibilities" even when what she wanted most was freedom. The imagery of this passage refers to her real life past, but also, it refers to the ways humans misperceive each other and reality, because that's what literally happens in her dad's case.
School before war
In Oxford, she studies at a college there which she describes as a radical change in scenery, which fascinated her and excited her to make new friends. She is a very social character in this setting, because she knows she is finally getting a chance to bloom. This represents a kind of sacred "enlightenment." But, it doesn't last for long, because after she finds her full personality, it is time for her to help in WWI, and the scene changes.
War in Europe
Brittain's account takes us to the front lines of combat, eventually being transferred to France where the trench warfare was most horrific, such that these scenes are comprised of almost absolute horror. She details the injuries, the strange psychic reality of the situation, because death was so clearly the issue in these scenes, but in the rest of life, it seems that life is about other things than death, but the imagery of WWI is a reminder that actually, death is the only real dilemma in human life.
School after war
Just like the academy changed after WWI, with the culture and the government, not to mention the economy, so also Brittain herself was changed by her own experience of war. We return to Oxford, but the feelings that used to be blissful are not melancholic. She is traumatized. Everywhere she looks, all she sees is trauma. She remains trapped in this hazy detached existence of overcoming her constant urge to panic, until finally a friend comes and helps her to process the emotional damage she has sustained.
