Many people with autistic disorder are not only pedantic, but are very literal in their thinking and interpretation is all from their own perspective. They find it near impossible to even understand that other people actually have a different perspective to theirs and assume that because they think a certain way that others do too.
If you suggest that you will be back in a minute and you're any longer, they may call you a liar and be quite viscous and non-forgiving about it too. They also have problems with generalising, where something may cost £4.98 and you say its £5, they will argue til the cows come home that it is in no way five pounds. I mean are you stupid it says £4.98 ?
However, our son also has issues with understanding the actual value of time and for example would struggle with knowing how long twenty minutes would seem. This also extends to monetary values too, he knows how much things cost to the penny, but has no concept of what that means to my wage packet.
He is very much into his i-pod, but has decided that an i-phone is now a necessity. With reasoned judgement he complains that he is the only one in the house who doesn't have a touch screen smart-phone, and this i can accept.
We have explained to him that he is after all only 9, and none of the rest of us have i-phones either but cheaper android type handsets. I have even offered to buy him a relatively low cost touch screen phone but this was rejected immediately because android phones are apparently rubbish and don't have the functionality of the i-phone 4S. He also pointed out that the white 16GB one only costs £573.65 on Amazon.
At every opportunity he recites all the features of this phone as he has researched it endlessly on youtube and Apple forums. He also takes every other moment to remind us all how unfair it is that he doesn't have one.
I have explained that the cost of this phone is too high and we simply don't have that much money. Which was quickly responded to with the riposte "but you had enough money to buy a new car, so you are lying" I have been as patient as I can, but trying to rationalise with him is not working.. I became angry and shouted at him there was no (and I may have swore) way that I was spending £600 on a phone.
To which he shouted very angrily................. its not bloody £600 its only £573.65 you idiot !