Do you compare your wife to other women? Not just how she looks, but what she does, what she says, how she treats you, and so on.
More specifically, do you think thing like, “I wish she dressed more like Rachel, treated me the way Gloria treats her husband, and was as openly sexual as Miranda.”
Have you ever considered some husband may be wishing his wife were more like your wife in some way? Sure, your wife has faults, but she also has strong points. There are things she does well. You can compare your wife to any other wife and likely find something the other woman does better, or more the way you would like. However, you can almost certainly find a number of things your wife does better or more to your liking than that same woman.
Comparison is a trap! If you look for where other women are better than your wife, or ways other marriages are better than your marriage, you can start to feel negative about your wife and the future of your marriage.
My suggestion is you compare your wife to herself. Thank her for what she does well, and complement her when she does better in any area.