We use a pillow for a number of reasons - to sleep with or for recreation or just for pretty. There is that soft, cushy pillow that just makes us feel cozy. Some people just like to hug them. If you are a pillow hugger, you can rest your chin on one when you're sitting on the couch and it just feels good and soft.
A Pillow will adapt its size and shape to fit you. If you put a one under your head, it will sink down under your head and semi-wrap around the sides of your head. Depending on how thick your pillow is will determine how much of it pushes up around your head. If it is dense, it won't so much.
Some people love to use them for pillow fights. This is where you can stand on the bed if you want to and really go all out. Mostly, nobody gets hurt by pillow fights. They are a fun way to release that pent up energy and a really great way to relieve stress. You will probably have to straighten up the room when you are finished. A lamp may change position or toys may fall off the shelf.
Pillows are used a lot for decorative purposes. Like on the bed. Pretty ones to match the comforter and the rest of the room décor. Pillows go on the couch, a pillow for the floor to get comfy when we watch TV, a pillow for in the car and a therapeutic pillow for backaches from pregnancy or other aches and pains or relief from injuries.
We even have a pillow specifically for toddlers.
I for one can't imagine a life without them can you? They are so much a part of our lifestyle that we can easily take them for granted. They've been with us since childhood and most likely we will use them more and more as time goes on and we get older. They are a necessary part of our lifestyle and I don't plan on ever getting rid of mine.