I used to wear thick, bulky pajamas to bed. Then, a few years ago, I tried wearing a silky nightgown. (Actually, it was polyester but it felt silky.)
Wow! What a revelation and delight! I loved the feel of the smooth, light material on my body and I especially loved how the nightie floated around me without the binding that pajama-bottoms cause. I felt free and comfortable.
Now, I own four nightgowns and wear one every evening. I still have the silky one (eggplant-colored with white lace trim), along with a long pink flannel nightie for cold winter nights. I also have two short, light cotton nighties in pretty pastel colors for normal wear.
You probably take it for granted but nightgowns hug the body in a radically different way than pajamas: they connect to you up top near your shoulders and bust and then fall freely beneath that. I love the feeling that structure provides.
I had an interesting insight recently. I observed that, with normal clothes, I like to wear outfits that look different from what others wear, to express my individual style. And yet, with loungewear, I cherish wearing the same kind of nighties that I see on other women in pictures and catalogs. I don't care about style with nightgowns; instead, I want to look like other women to feel a kinship with them.
If it's not too personal, what do you guys wear to bed?