Near the end of the play, Benedick says, “Man is a giddy thing, and this is my conclusion.” What does he mean by this? Why is this a fitting conclusion to the play?

I think that the running theme here is the inconstancy of human nature. It is a comment on how man may come to foolish conclusions in the absence of sober reflection. All the characters are illuminated to some point now and understand their fallibilities better. THat is a rather apt ending to this play.