The postdoc has done the maths. In the last 6 months, she has slept in 18 different beds.
At first, she experienced the thing where you wake up and wonder where you are.
Then, she gently moved into the phase where you assume you are not where you were yesterday, and simply review the situation anew every morning.
Now, whenever she is home (whichever home) for a few days, she gets nervous and goes to sleep on the sofa. Just for a change.