I never thought I had seasonal allergies, having made it through 30 years of seasons without issue. Apparently, however, I am allergic to Mountain View in late March. March has passed, as have my allergies, but now the mystery remains: what is in the air in Mountain View in March that isn't in the air anywhere else that I've lived at any time of year?
My only other allergies that I know of are cats, rabbits, large quantities of dust, and Sulfa drugs. Maybe someone tossed all of those into a wood chipper and sprayed it all over town, but just for a few weeks, until it got old?