What is it about Wednesday?

By late afternoon on Wednesday during an average working week I always feel completely worn out! Why is that? More than any other time of the week I feel tired and grumpy, and I always feel like I need a glass of wine and /or a nibble of something sweet or chocolatey! Well, this evening I have done both, I've had  lovely glass of very chilled chenin blanc, and a banana muffin....and do you know what?...., I feel better for having them both!!! Not sure how I'll  feel about that when I step on the scales at the weekend though!