Harry got the second wave. He did not experience what the generation before him did.

[ Severus is quiet for a moment, considering. He has no idea how to properly explain. ]

War for us is not like it is for you. We do not have a military. It is small scale and personal and touches every one of us face to face. War is families being murdered in their homes, assassinations, children abducted and their parents tortured. Half of my students are orphans. Half of the ones that aren't have parents in hospital permanently or in prison.

Black has not experienced the war. Lupin has. I have.