The other day, I found myself suddenly pressed to explain the concept of public key cryptography in a google-free environment.
So I awkwardly tried to stammer through an explanation of the basic principle of creating mathematically linked public and private keys using an irreversible operation; namely, that it's computationally easy to multiply large numbers but computationally difficult to factor them. In the process, I came up with a large number off the top of my head - 74,257 - and used it to demonstrate the difficulty of finding a number's prime factors.
The minute I made it back to the internet, I double-checked a suspicion that had been bugging me for hours, only to have it confirmed— 74,257 is, in fact, prime.
So in the process of trying to explain the complexities of prime numbers, I inadvertently came up with a five-digit prime number on the first try unaided. Thanks to the miracle of confirmation bias, I will now believe that I have a supernatural knack for coming up with prime numbers on the spot and proceed to make a colossal fool of myself.
PS: I'm still not talking about Brexit. Maybe if I ignore it for long enough it will retroactively have never happened.