This isn't tiredness. Tiredness you can sleep off. This you can't. You lie down, turn over, tell yourself he's probably just busy, and then reach for the phone again.
Scientists have actually watched this happen inside a machine. They put people who had recently fallen in love into an fMRI scanner and showed them a photograph of the person they loved. The areas that lit up specifically for that face were the right ventral tegmental area and the right caudate nucleus — dopamine-rich regions tied, in mammals, to reward and motivation.
Motivation. Not joy, not grief. In the brain, love got filed next to thirst and hunger. And you know how well "just think about something else" works on thirst.
So waiting hurts because you are not being crushed by a feeling — you are being given an assignment. Write. Go. Hear her voice. That whole system exists to get a person up off the sofa. It won't leave you alone, because leaving you alone is not what it was built for.
The researcher who ran that study once described being in love in an interview in plainer words: it's like someone has camped out in your head. And you can't get them to move.
One more thing from her. She separates love into three systems that run on their own schedules: sex drive, romantic love, and attachment — the quiet, settled kind. They don't have to arrive together, or on the same day. That's often what's behind months of "do I love him or do I just like him" — one of the three is still on its way.
So if you're opening an unanswered chat for the tenth time tonight, don't be too hard on yourself. Blame the right caudate nucleus. Just tell it to go to bed occasionally.
If nobody has camped out in your head yet, start meeting people on YOR YOR today.