This is what it feels like for me (an autistic person) to change my routine or add to my routine.
Reality to an autistic person is a confusing, interacting mass of events, people, places, sounds and sights... Set routines, times, particular routes and rituals all help to get order into an unbearably chaotic life. Trying to keep everything the same reduces some of the terrible fear. Jolliffe (1992) in Howlin (2004), p.137Also-
Routines play an important role in the lives of people with autism. The everyday hustle and bustle that most people view as normal can be an overwhelming combination of frightening crowds, intimidating sounds and overbearing lights for people with autism. Routines help to create stability and order.
People with autism quickly learn routines and are naturally motivated to repeat them. If the steps in a routine are presented with a clear beginning and end, the total routine is often learned quickly. Since people with autism are naturally motivated to repeat routines, the completion of the routine is in itself reinforcing. This includes daily, weekly, monthly and annual routines, as well as structuring tasks as consistent routines.
A reliance on routine to provide certainty in the lives of people with an autism can potentially lead to their behaviour becoming ritualistic and obsessively rigid. This may be most evident during times of change or disturbance. If this occurs it is possible to support people away from this behaviour towards a more balanced approach to routine.
So anyway, there you go. A visual for you