Dreaming about being in a hallway in a house typically means that the dreamer is doing some self-reflection as in "going through" his house (self). Sometimes, it means that the dreamer is in a transitional phase as he decides which room (aspect of himself) in his house to enter.
Some of those doors led to rooms filled with great memories. Yes. We all store our happy memories in different parts of our minds, don't we?
And yet, we all seem to have places within that contain all of our fears, regrets, repressed memories, and yes, all of those horrifying images that assail us from the darker side of this world.
Your higher self is showing you all the compartments within your "self." Pick and choose which parts of yourself you'd like to nurture and spend more time in. Which parts of yourself could use some cleaning out or coming to terms with?
Above all, remember that you have the power to choose which doors to open and which doors to close.