Let's unpack that sentence. I'm flying, which is to say the vehicle that's carrying me is airborne. The bridge in question is the last bastion point of humanity. Not that we need one. I personally believe that humanity is extinct. Except that I'm here, and even if I wasn't the bridge would still be standing (to say nothing of my plane, but I already have), a solemn reminder that architectural immortality is a sad similacrum of the real thing.
Where there are bridges there are trolls. Three billy goats taught me that once. I've forgotten their names.