As written, it says that I could be on board the plane minding my own business, but because someone else hasn't boarded they can reassign my seat. The expression is intended to convey that you really don't care. But, if you could care less, then then you really do care. A podium is something you stand on . A lecturn is something you stand behind .
People are of a particular sex .
Since the 14c. I'm assuming there is a name for this construction, but I have been unable to find one. The leftmost version sounds very odd to me, although since noticing its use by others, I've caught myself using it once or twice. He couldn't think of a name for it. The standard alternatives are shown in 2.