To keep you asking this.
Having you wrapped around his finger
It's a manipulation strategy

The goal is to make you feel validated (I want you ) yet confused (contacts On your birthday, ghosts you after) mixed signals (affection and rejection) so you must try to reach him for clarity.

The worst you can do in his mind is to not react or care at all. He is waiting for you to come crawling.

He's playing games with you, and he's an ex for a reason, so why continue wasting your time on him? Move on

You have your answer/

It sound , to me, like he thinks of you infrequently and likely when he isn’t occupied with other thoughts. Meaning, he isn’t thinking of you all or most of the time, only when he doesn’t have something else he’s thinking about. FWIW.

Wow lots of cynical comments here.
Who left who the most recent message?
If it's him, and you haven't responded, maybe he's conscious that he mustn't be seen as being too pushy. Or, leaving the ball in your court.
I'm still in touch with some of my ex's, we're genuine friends, each of us have moved on but there's no difficulty in our friendship.

One day eventually doesn't mean right now, doesn't even mean at this point in life. Means don't be waiting, maybe in another lifetime, somewhere well in the future though

Move on

He wants an ego boost ...don't waste your time

Has this changed at all as we approach your birthday? Perhaps THIS birthday will be his "one day"...?

Twitter/X is his usual social network and he has a memory span of approximately ten minutes?

He wants you to approach him and do a minimum for that on his side. Sounds like manipulation to me.

Probs just misses you or is looking for some attention.

Good to see you sweet lady. Protect yourself.

Maybe he has nothing to tell you ?

Wish washy? He is to indecisive to be a man

He’s playing games with you ,, move on and forget him you’re better than him x

He left. Leave it be. His loss. Move on

Not sure

It was a booty call

You shouldn't talk to him

Nope! Screw that dust flake! He is the past and belongs there. What’s the point of being friends? Are you gonna invite him to your wedding? Or is he gonna be the friend that you just text here and there? because idk about you but that’s not really a friend, that’s a question mark. He just wants to keep tabs on you and see if it’s worth getting back together. He’s pathetic, I hoped you dumped him bc he wants his ego stroked thinking you’re just waiting on the side for him.

He's a liar

Tell him you're more content without him and breaking up was the best birthday present he could have given you. Then block his narcissistic ass.