I am, of late, having mild frequent "blasts" of smells unrelated to anything I'm near, wearing, down-wind of, or can identify. Is this a neuron gone crazy thing or do I (yippee) have something else coming up in my rearview mirror?

Thanks to all.
Pat
Ps if there really was a thing that gave a real rear view I would not own it because glancing at it sidewise is bad enough!