Under The Weather

That's what I've been thinking. I just haven't been feeling myself. Well what does that mean, "Under the weather?" Here's what "Go English.com" had to say:

To say that someone is "under the weather" is to say that they are not feeling very well. Example: "What's wrong?" Answer: "I'm a bit under the weather." They probably have a simple cold or flu which will go away quickly. Example: "It's nothing serious; I'm just a bit under the weather." Being "under the weather" reminds us that a quick change in the weather can affect our health and the way we feel.

So, is it because of the weather, now I'm confused. I suppose it could be. In this case, I think not. My head and tummy have been feeling yucky. Hopefully the weather and my health will improve!