If a giraffe has two eyes, a monkey has two eyes, and an elephant has two…

Lateral-thinking riddles like this one hide the answer in identifying who a pronoun such as ‘we’ or ‘you’ actually refers to, rather than in the facts stated on the surface. The stated facts are often a deliberate distraction from the real referents.

Here, the eye-counts for the giraffe, monkey, and elephant are exactly that kind of distraction — none of those animals are part of ‘we’. The word ‘we’ refers to the two people actually engaged in this exchange: the person posing the question and the person working out the answer. Each of these two people has two eyes, giving 2 people × 2 eyes = 4 eyes in total.

• 2 would only count one of the two people in the exchange, missing the other participant.

• 1 does not correspond to any whole person's eyes.

• 3 cannot arise from counting whole people in pairs at all.

Only 4 accounts for both participants, so we have 4 eyes.