Anyone who has spent any time in airports over the last twenty years has seen multiple display stands featuring travel pillows being offered for sale. They are pretty much all the same, designed to wrap around your neck so your head doesn't shift while you sleep and wake you up. The more expensive ones are filled with some kind of beads or seeds, while the cheapo versions need to be inflated with your own lung power before you attach it to your neck and try to get to sleep while being worried that it will lose air during your nap and you'll wake up with a crick in your neck and the guy in the next seat trying really hard not to snicker.
I actually own a travel neck pillow thingee which is filled with beads or seeds; I've used it on long (11 hours on paper, 12+ in reality, all the time, because America) train trips. It works ok, but it's obviously limited in it's utility as it will not prevent your body from shifting sideways as you sleep. This is a big deal if you are one of those people who can fall asleep on a train, I guess. I wouldn't know, because I'm not one of those people.
Anyway, here's a commercial for what I can best describe as a larger, more cumbersome version of the travel pillow. It looks a lot like something I saw being advertised in one of those SkyMall magazines that sit in the pocket in front of your seat on American Airlines flights. It goes a step further from providing stabilization for your neck and actually provides a mini-bed for your entire upper body to rest on. You have to inflate it (which means you have to worry about it deflating, but let's be real- this thing isn't going to sell if it's filled with beads, weighs 15 lbs and counts as your carry-on) but once you do, you've got a little comfy personal space to lean into to take a nap or watch movies on your phone (without headphones, of course.) Heck, if it isolates me from the person sitting next to me, maybe it's even worth it.
But seriously- can you imagine using this if you aren't in the window seat? Put it another way- how'd you like to be in the window seat and have the person in the aisle seat using this? You're sitting there about to take off for a six-hour flight and the person sitting next to you, blocking your only exit to the restroom, is announcing "I'm going to be completely oblivious to you, probably asleep, in a few minutes- if you want to get up you'll have to interact with me physically, and btw this is also going to make it very difficult for you to get your drink or your meal because I'm basically creating a wall between you and the rest of the plane."
You know what? Just get one of those travel neck pillows at the gift shop and accept that you can't recreate your freaking bedroom for the flight. You aren't the only person on the plane. More to the point, you aren't the only person sitting in that row. So unless you have the window seat, you don't get to use one of these stupid things, ok?