I am thinking about writing a fantasy fiction (casually, mostly for my own entertainment), would the style of a memoir be suitable?
More specifically, the writing would be the personal account of a fictional character on his experiences of the past.
The fantasy part would be this: the world is like the one we have, up until 2015, when magic "invaded" it. A bunch of people died and an apocalypse started, the narrator struggles to survive in the post-apocalyptic, magical world. The memoir is written after everything got better.
My question is, is there any obvious problem with this style for a fantasy fiction novel? For example, would there be many situations where it would be natural for the character to talk about things involving magic but the reader may not know enough background for the conversation to make sense? Also, would the fact that the writing is a memoir suggest to the reader that no matter how intense things get, the narrator will survive, and thus removing the tension and excitement? If so, is there any way to achieve those effects in this style?