People who care for you will never forget you, but bothering him while busy, will not make him happy.

The only way he's going to miss you is if you move on... Get happy by yourself.

Not act like you've moved on, actually move on.

Funny quote I read on here recently: "How can I miss you if you won't go away?"

Your leaving him be and diving into your next big adventure has many benefits:
You are not wasting time on a guy who may have just been letting you down gently and has no intention of coming back
You focus your energy on what is real in your life, not wished
You immediately become actually involved in your present and making a new life
You might stumble onto someone/something way better than this guy, give it a chance
As long as you truly move on with your life, getting involved in your next relationship(s) and adventures, you're not wasting time on dead-ends, which is what he is right now.

A year from now, you will be busy having a great life doing other things with other people, or he will have come back and YOU decide to let him. But you have to be OK with either result. You win.