For some reason this thread bumped back up in my notifications and I am now re-reading the later responses.
I believe genetic memory is real, the issue is that we dont know enough about the power of our brains to take advantage of being able to recall these memories willingly or in real time. Someone made the comment earlier in this thread to the effect that an interest in a battlefield or interest in the CW will stir these feelings that can be misunderstood as a "past life". I agree that the concept of a past life or reincarnation may be hard to accept, but this is vastly different than the concept of genetic memory.
What I believe happens is that an intense study, interest or passion in a subject may inadvertently open a pathway to bits and pieces of this genetic memory and give us the smallest glimpse that may only manifest itself as simply a "feeling" in most people. I am convinced I have a snapshot in time, a view of the light/ground at Vicksburg that came from my GGGrandfather, its really just an camera obscurra looking image of light and earth that could be anywhere, but I am convinced of what it is, as it simply manifested itself in my memory several years ago. I believe I could be able to see more, but I dont know how. I also believe that my intense passion and study for the war, Vicksburg and my Ancestors somehow made this connection without my will or knowledge.
If my passion was shoe making and I spent most of my life thinking about and researching the subject, then possibly this could have occurred with a feint image from the mind of an Ancestor who was cobbler. We may never know.