A lot of people with ASD have difficulties with change, and need structure. It makes us calm, makes us know what is expected from us. The world is full of change, and we need a way to cope with it.
To do this, I create structure, routine. We want to know what is going to happen, and have a hard time just ‘living life, and waiting for what comes’. Planning is our life, and a mirror into the future would be great :).
Some people on the spectrum might need a relay tight structure, and will crash when things don’t go as they expected. They want to do things on the same place, same time, same way, day in and day out. This is a way of coping with change. If everything is planned, structured, the same it will not change as much as something that is changing continuously.
Breaking this structure might give some stress, where some are able to deal with it if it is announced a certain time before the thing changes, as this still gives predictability.