In my experience if you are encountering a coincidence occuring, people present and also observing the same coincidence won't register the fact until after you've gone to tremendous lengths to explain.
Much rarer is it when that happens and someone else sees it and you know it, the telepathic, "Whoa!"
I think people are mostly reluctant to register connectivity phenomena.
I wonder why?

Reason and odds?

I would like to attempt a concise explanation – but of course any explanation of why our reality is the way it is would require a much longer answer (like Jim’s book for example).

1. In the program, your reality and my reality must only coincide (agree) to the extent we actually interact – and then only to the necessary extent that our realities require. i.e. there are people out there with whom none of us has ever met or interacted with and their version (perception) of reality can be (most often is) very different from ours.
2. The program can use this advantage to the extent necessary to ensure that our experiences (mine and yours) are catered to us individually to help us most in our own “soul’s” quest for this higher self-awareness. (see determinism, the “illusion of free-will” discussed in other posts or just google the topics)
3. This grand “program” – the “experiment” the “game” the “experience” the created human “soul” – is very flexible in that way to give us the best opportunity of reaching that self-awareness or “enlightenment.”
4. This is an extremely finely tuned process that we cannot even begin to imagine, but things like memory, sleep, dreams, etc. all play into the program and its ability to manipulate reality as is needed and still keep everything consistent enough.
5. There are bound to be anomalies and in the course of a lifetime chaos theory would tell us that the anomalies are probabilistically more likely than not. i.e. for Neo’s experience there were thousands of other opportunities to visit a bookstore and millions of other people where no Joan Keogh was needed. The chances of another Joan Keough being there at that one instant are very small, but the chances of another Joan Keough randomly showing up are high (again chaos theory). The program just made a very quick adjustment and you have no fool "proof" evidence that the programmed reality exists, but none-the-less, it leaves you wondering.

Neo: Whoa. Déjà vu.
[Everyone freezes right in their tracks]
Trinity: What did you just say?
Neo: Nothing. Just had a little déjà vu.
Trinity: What did you see?
Cypher: What happened?
Neo: A black cat went past us, and then another that looked just like it.
Trinity: How much like it? Was it the same cat?
Neo: It might have been. I'm not sure.
Morpheus: Switch! Apoc!
Neo: What is it?
Trinity: A déjà vu is usually a glitch in the Matrix. It happens when they change something.

The Matrix (1999)

Spooky coincidence at work today:
A client was sitting next to another non-client with the same first name. The other 'non-client' also had the same Surname, as another person sitting two people across from him, and the waiting area only held about eight people.
Thinking about it logically, a good proportion of people were called in alphabetical order, so the chances are pretty hight that a shared surname would occur. Still, it made me think, and make note of the event here.