When the other half is home we switch depending on how we sleep to begin with usually he is against the wall but now he is on the outside and I am by the wall. Now that he is on the road again I sleep in the middle
If we're laying in bed together, I'm on the left. But because our schedules are so different, we're only in bed together about 2-3 hours a night so we both tend to sleep in the middle when we have the bed to ourselves.
I have a California King all to myself (well me and my dog lol) and I currently sleep on the left side (when laying in it). My fiance is moving in soon, and he wants the left side...we will see how that works out