My brother has been diagnosed with autism. He has very set unusual rituals or routines and can get very upset at changes in routine. One of them is number of time he touch the lightswitch. 

For example: if he turned the light on, he has to be the one who turn it off. It would count 2 times  touching the lightswitch. If anyone interupt that 'routine', he would get very frustrated and he would assumes everything bad happens because of that incident.