Why Does No One Remember Past Invasions In Doctor Who? [duplicate]

Question

After watching the recent New Year's episode (Resolution), something has been bothering me. A Dalek is encountered on Earth in 'present' times and attempted extermination ensues. Nothing that shocking there, except that everyone aside from the Doctor reacts as if they have never seen or even heard of a Dalek before. Thinking about it more, this seems to happen on most occasions when a recurring threat shows up on Earth. Outside of the Doctor and perhaps a few government types, everyone reacts as though this is a completely novel situation. That in spite of the fact that the menace of the day has tangled with planet Earth within the living memory of these people (multiple times in the case of Daleks and some other popular foes).

I can understand smaller events that happen in isolated places or only affect a small group of people. Those could be covered up or simply dismissed as a hoax. In the case of the Daleks though, they have staged mass scale invasions on a global scale on multiple occasions. Kind of hard to forget millions of murderous pepper pots dropping out of the sky.

I understand why the show does this from a story perspective. Companions are the audience proxy, so they need to be in the dark to provide an excuse to explain things to the audience. Likewise, any serious efforts by Earth to protect itself from 'next time' would undermine the need for the Doctor to show up and save the day.

What I'm interested in is whether there has ever been an in-universe explanation? Do human beings just have the memory of a goldfish or is something else going on?

Answer 1

I used this as an answer in another question, very similar to this.

The 12th Doctor once try to explain this, back in his first series. He claims that forgetting "traumatic events" is humanity's super power:

(From Series 8 "In The Forest of the Night" after the Forest comes out of nowhere to save the planet from a solar flare)

CLARA: That is amazing. How will they explain this tomorrow?

DOCTOR: You'll all forget it ever happened.

CLARA: We are not going to forget an overnight forest.

DOCTOR: You forgot the last time. You remembered the fear and you put it into fairy stories. It's a human superpower, forgetting. If you remembered how things felt, you'd have stopped having wars. And stopped having babies.

This is, in my opinion, the wakest episode of the 8th series, and a very weak explanation.

There's also Amy Pond not remembering the Daleks in series 5 episode "Victory of the Daleks":

DOCTOR: Amy, tell him.

AMY: Tell him what?

DOCTOR: About the Daleks.

AMY: What would I know about the Daleks?

DOCTOR: Everything. They invaded your world, remember? Planets in the sky. You don't forget that. Amy, tell me you remember the Daleks.

AMY: No, sorry.

DOCTOR: That's not possible.

Only that time it was explained with the cracks in time and the Doctor rebooting the Universe.

So in short, Doctor Who doesn't usually work well with its own continuity. Some explanations have been tried in past episodes, but it the end of the day, you shouldn't let it bother you too much and just roll with it.

Answer 2

Past Invasions are remembered in Dr Who, when the DR calls to try and get in touch with UNIT she is told it has been closed down due to Funding restrictions, when challenged as to who is left to deal with an Alien invasion the women on the phone states "we haven't had one of them in ages" indicating at least some people remember the past attacks and invasions on Earth.