Imagine two water-filled sacs covered in velcro tape (both hooks and pads mixed on the same surface). The surface of contact is very flexible, but quite sturdy, although each individual connection is not very strong (a single hook of velcro). That would be a very good imitiation of real life. To make the picture complete you can imagine different kinds of velcro in small patches - some are very strong, others are weak, some stick only to their own kind others are pretty general.