Which side of the bed is the left side? Is the answer based on the perspective of laying in the bed (person’s head at the head end)? Is the answer based on viewing it from the foot of the bed, looking at the head of the bed? Is there an “anatomical position” or special terminology like in boating for this?
For context: My boyfriend and I can’t agree on this. We change who gets which side based on the shoulder we’d predominantly sleep on and how it’s feeling. This let’s us get good cuddles before shoulder pain gets irritated. He comes to bed after me. A while back he asked what side I’m sleeping on. I said “left”. Later that night, he comes in and almost lays directly on me because he claims “left” is the other side. Since then we have to describe which side using complicated descriptions.
Ah, but as you say, people only care when they’re “going to” lay in it, meaning they’re not in the bed yet. Once you’re in bed, you pretty much never need to specify the left or right side, you can say “shit, i spilled a drink on your side!”
So, since we only care about left and right sides while we’re not in bed, I say who cares about the in-bed perspective. What matters is how it is oriented while you’re standing up and looking at it. So that’s how I’d assign left and right side.
To that, I’d say it’s likely better if we use landmarks. Identify unique furniture or a window or something on each side. Then, refer to them as “Window side” or “Lamp side”.