First, there’s the issue of side. Which, if I’m sleeping alone, is the left. But I’m flexible on that one. Either side of the bed works well enough for me, making the choice an easy first concession.

Then there’s pillow selection, which I’ll also happily give up, for the good karma, and the illusion of being accommodating.

The trouble sets in with sleep position. Left to my own devices, I’m largely a stomach sleeper, with occasional side forays. Most girls, however, seem to covet the shoulder/neck nook as pillow, which necessitates back-sleeping. Or, rather, back-not-sleeping. Because, as comfortable as the position actually turns out to be, I can’t really sleep in it. Spooning’s a bit better, though I’m never quite sure where to keep my bottom arm.

Sooner or later, it’s some slightly separated yet leg-intertwined position. Which works well for the most part. Except that a surprisingly large percentage of girls seem to kick involuntarily while deep in REM. Some, the former soccer or field-hockey players the worst amongst them, kick hard. All deny it once awake.

And, of course, all girls steal the blankets, somnolently bunching comforters with reckless disregard for their co-coveree.

A large percentage, too, are total insomniacs. Or, perhaps, just a large percentage of the ones I like, given my prodigious ability to develop crushes on smart yet totally neurotic girls. They can’t fall asleep. They toss and turn. They wake up in the middle of the night, then wake me up to announce that they’re awake. Or they steal my computer and respond to their work emails from three until four in the morning. Or they do both. The same girl, night to night, is utterly unpredictable.

Or, at least, seems so at first. But, inevitably, there’s (some) method to the madness. Which is what bed-sharing – and, perhaps, relationships in general – is really all about: spending enough time with someone to figure out their idiosyncrasies, to determine how those line up with your own, then compromising, practicing. All in the name of somehow finding that comfortable, sustainable, “I could sleep like this for the long-haul” groove.