Optimism, that is what the Doctor really likes about humanity.

The secret of human happiness will be cracked in the future.

Robots created by humans in the future speak Emoji.

The Twelfth Doctor is not fond of fish.

No other species in the universe uses Emojis.

The Doctor has two hearts, that also means he has really high blood pressure.

Smiles are not just smiles. Psychologically they have a measurable effect on your mood swings.

The Doctor is not Scottish, he is just cross.

Scottish people are everywhere in space, demanding independance from every planet they land on.

Why does the Doctor keep the TARDIS as a police phone box? It is stuck (the Doctor). He is the helpline "Advice & Assistance Obtainable Immediately" (Bill).

Every spacecraft needs a door.

The Doctor is allowed to blow something up and he will not get in trouble, when it is a moral imperative and it is a machine.

Earth was evacuated and the Doctor bumped into a few of the ships over the years.

The badges, wearable communication, are meant to communicate satisfaction, a positive mental state.

The Vardi never heard of grief before and identified it as the enemy of happiness.

The Vardi think different, like the Magic Haddock: not bad, not good, just different.

What is the opposite of a massacre? A lecture (the Doctor).

The Vardi are a new species.

Every computer has a reset button and any one can find it. Especially if they happen to be a scary, handsome genius from space.

The colonists will have to pay rent to the Vardi, if they want to stay in the city.

The Doctor flies around, sorting things out, like some kind of intergalactic police man.