Well, it matters to me with or without a memorial, but I have to say a physical memorial is a very good reminder, and a statement to those of us who weren't actually around at the time.

As a matter of interest, up the road from where I live is Cannock Chase, the remnant of the ancient forest. In it are the Katyn Memorial to the Poles murdered by Stalin and the German Military Cemetery. Both are tucked away among the trees, but both get plenty of visitors, and not just from relatives and friends of those who died. The German cemetery covers both wars; there are a lot of kids in there ... sorry, I'm rambling now.