Help with more sensible lifespans

So as I’m sure many of you are aware, many of the races in the dnd universe live for a very long time. Humans are considered short lived and don’t often make the 100 whereas a lot of the more common races like elves and dwarves can often live multiple centuries and might even approach a millennium if they are lucky.

But I find this causes issues with the history of worlds I create. If something happened 400 years ago, that’s still in living memory for a large proportion of the population especially in the socially integrated worlds I tend to write or that official campaigns are set in.

So my question is how have other people dealt with this situation? Do you just ignore it, or do you use a set of alternate lifespans? I don’t want to go down the route of “everyone lives till roughly 80”