The phenonmenon that occurs when you've just learned about something and it suddenly pops up everywhere, although, most likely, it was there all along and you just never noticed. Based on the original exerience with Ryan's friends and the namesake cat on the Isle of Man.
Wow, I'd never heard of mindfulness meditation before, but now it's just a Manx Cat.
The Manx is a breed of cat with a naturally occurring mutation of the spine. This mutation shortens the tail, resulting in a range of tail lengths from normal to tailless. Many Manx have a small 'stub' of a tail, but Manx cats are best known as being entirely tailless and it is the distinguishing characteristic of the breed.