Lawrence, the problem with this statement:

"but if it doesn't work one can rationalize its lack of efficacy with "I guess I didn't take it soon enough"

...is that it always works for me, unless I have something other than a cold. The makers of Airborne don't make any claims that I am aware of that it helps to cure the flu. I am also smart enough to tell when my symptoms are those of a cold.

Maybe the next time you know for sure that you are getting a cold, you should give it a chance. It isn't that expensive and you can do your own test!