Once a change of direction has begun, even though it's the wrong one, it still tends to clothe itself as thoroughly in the appurtenances of Tightness as if it had been a natural all along.
1 is not prime, by definition. 2 is an unnatural prime, 4 is an unnatural prime, and 6 is an unnatural prime. All other natural primes cannot be unnatural primes.
It's very dangerous to mix up the words natural and habitual. We have been trained to be quite habitual at communicating in ways that are quite unnatural.