Bought this for myself, a grownup, because I'm 5'1 and most adult turtlenecks are too long for me so I guess I have a short neck. It fit perfectly and I definitely feel like the regular size would have been too big.
I was skeptical at first but it really does work. I flew 17 hours across the Pacific in economy middle seat. That would usually be a death sentence but I actually slept at least 12 of those 17 hours thanks to this pillow. It cradles your head very well and can be used on the left or right (I switched it 2-3 times). Someone was watching a movie on full brightness but the fleece can be raised above your eyes slightly to block that. Bonus that it packs semi flat and you don't have to walk around the airport with a neck pillow on.
10/10