When I'm on a furniture and I change position, I almost always want to remain on the furniture. Sometimes this happens by default and sometimes it doesn't.
i.e.:
sit cot
rest --> I want to rest on the cot, not stand up and rest on the floor
sit --> I want go back to sitting on the cot
sleep --> I want to sleep on the cot etc etc.
Again, I think this works with some furniture and not for others (even if the furniture supports both sitting and resting).
The, like, one exception ever is that I probably always intend "stand" with no arguments to detach me from the furniture, like:
stand bar --> standing at the bar yo
stand --> You push away from a boxy boxy bar.