SCP Foundation

An immortal businessman who is always talking to someone over the phone. He says things like "Of course!" and "No, no, no!" and other variations on "yes" and "no". He says other normal business things, but he mostly gives affirmatives and negatives.
Now, he was taken into custody because he was immortal (he got hit by a car and lived, still talking on the phone), but someone noticed that there was a pattern to his yeses and nos. This person started keeping track of his monologue and tried to decode it. He started keeping track of the words, eventually compiling a book several inches thick. But he had no idea what to do next.
He was then, somehow, coincidentally, IDK yet, reminded of the old saying "binary is all ones and zeros," and something clicked. He opened up his big list, used a good old find and replace tool to make "yes" to "one" and "no" to "zero," and entered the resulting string of binary into a Foundation supercomputer.
Immediately, it started compiling. After hours of waiting, the computer finally finished, and autotyped the following words-
HELLO
WHO ARE YOU
WHO AM I
WHAT IS
WHAT IS NOT
EXIST

Cooky immortal isn't the most original thing in the world, but it can be done well if given an interesting twist. Communicating in binary could work as your twist, but only if the things he communicates are actually interesting. These rather generic philosophy questions are a poor payoff to the buildup, and introduces some plot holes regarding the size of the notes and the person with whom he is communicating.

This reminds me of my own SCP-1442, which is a corporation that communicates in a similar way. In that I made the idea more interesting by exploring what the intelligence would seek to communicate with (other corporations) and, at the end, giving some insight into how it thinks and how it actually feels about its predicament.

You could perhaps do something similar here.

The binary is the code of a super-advanced self-aware AI. Something something MCD, something something illegal and discreet transmission of AIs to wealthy customers.