Every time I think about WWI, it seems like about the most miserable and terrifying war conditions I can imagine. But then when I watch old interviews with WWI

Every time I think about WWI, it seems like about the most miserable and terrifying war conditions I can imagine. But then when I watch old interviews with WWI veterans they all seem unusually chipper about it. Really kind of confuses me. Not sure if it was just a different time or if they had just repressed all the inhumanity of it.