I think you have to go back to when you were a little kid. I know that now I understand sarcasm and probably use it sometimes too. But that has been learned over the years of being around people and observing. I remember being a little kid and not understanding why anyone would say anything for any reason other than to convey a particular message that needd to be comunicated for a particular purpose. This would exclude small talk, randome meaninngless chit chat, sarcasm, and jokes. When I observed these types of comunication amoungst others it puzzled me.
EXample... I was about 11-12 and was around some same age cousins. The cousins had a young brother. The little brother was takeing a drink from one the the my age cousins cup. The other my age cousin said to the one who's drink he was drinking out of something abut little kids drinking and leaving backwash in the drink. I think there was some back and fothe sarcasm between the two about that. Non of it made sence to me. Why would such a thing be necessary to say? (remember I only thought of comunication as a way to convey necessary information). I rmember being puzzled and asking my Mom why my cousin had said that. My Mom said something like 'O she's just messin whith her'. Saying something to 'mess with' someone made no sende to me. (remember I only understood comunication to be for relaying a message for a necessary purpose)
I have used the example before about being in kindergarden and takeing a doll in for show and tell. the teacher asked me abut some ink markes on the doll. I told her my little sisters did it. she said... , "well they'r just little monkeys arn't they?" I was really confused as to why my teacher would think my sisters were monkeys. i told her 'no theyr people'
Of course now I understand when I hear people 'messin' with someone. And if someone calls a little kid a little monkey I know they don't really think the kids is a Monkey. But this has been olearned by obaserving people over the years. Now I call my ltittle grandbaby anything from my little punkin, little monkey, a little fart head lol.
so yea I can compleatley understand why one would say an aspie would not understand sarcasm. They are talking about me. I think they are not saying that it can't be learned but that it dosn't come naturally in us like others.