I share your theory. I haven't had full blown flu, just stomach flu years ago and after the 1st time, if it was that same "bug", it affected me less each time and have never had it since and never got "the shot". I did get some respiratory congestion about a month ago, but never felt sick and it cleared up in about a week. Could have been Wu Flu, don't know, don't care. It's gone & I'm still kickin'.