The dream opens in a place, and the place sets the theme: it took place in a childhood home or school, which points to patterns, feelings or lessons that began long ago and are active now.
Then comes the turn of the dream, where its symbols appear: a house, yourself: each room a part of your life or mind; the sea, the great unconscious, and the feelings too large to hold; a door, a threshold, an opportunity, or a part of life opening or closing; being lost, uncertainty about direction, or something missing; a key, access, solutions and what is kept closed; water, feelings: their depth, their flow and whether they feel safe; teeth, confidence, appearance and the fear of losing power or face.
And the ending shows where things stand: you woke up suddenly, at the peak of the dream: the mind often wakes us at the moment a feeling becomes too strong, which marks that moment as the heart of the dream.