I'd say an unusual perspective- but beyond that, a tendency to think, and thus have thought, of odd questions and situations. For example, in situations where people ask me "Any questions?", I'll sometimes (when it seems appropriate, or at least only mildly inappropriate) reply with something along the lines of "If we'd been an aquatic species, but otherwise the same, what kind of musical instruments would we have invented?".

The usual response is a baffled stare, or a "Good question!", or a laugh and an "Any relevant questions?", but if anyone actually had, or could come up with, a real answer, would- to my mind, at least- be someone worth befriending on the spot. You KNOW you'd get interesting conversations out of that.

They strike a chord that resonates with you uniquely.

When you are having a conversation that is interesting to both people.

Finding that we have had similar experiences and how we share the feelings, prospective and ideas on them.

I would like to talk with someone if it looks smart, interesting or funny.

A conversation that naturally flows
Am interesting topic increases the pleasure of that conversation

I'm not a big conversationalist which makes people confused since I post so much on here.
I think I disappoint them I do give one word answers.
It isn't all the time ,but the motivation is only that I think a one word answer will do in some cases.

I appreciate people who know my intent and realize my character.
I have collected quite a few over the years.
We are okay with only message each othering once in awhile and nobody gets hurt and stops being friends- I appreciate that.

What I expect out of the conversation is respect and not expecting me to give them what they expect that I should in their mind- as I can't read them.
Expectations do have to be verbalized or you can't expect other people to meet them.

What Lil said:

I don't like the idea of private chat. And maybe one in a thousand would care to discuss what I like to.

If I get one-word responses I take it as a hint they don’t want to talk. That’s ok. If someone puts in the effort to find our commonality I appreciate it

lately nothing,id rather not talk,