Not doing things that are not of interest
Limited interests can be stated as a characteristic of Asperger Syndrome. While we tend to get carried away with things of interest, we do not even touch things that we are not good at or uninterested in.
For example, I am not good at managing my money. "How much is being taken out of my account each month" or "How much money is left in my account" are things that I never kept track of. I was extremely lazy.
When I told one of my few friends about this, I was told to "do something about it". However, I was uninterested, so it went in one ear and went out the other. This is despite my friend caring for me enough to tell me so.
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As one with Asperger Syndrome, I do not do things that I am not interested in. Thus I did not manage my money.
At some point, my friend asked me this:
"You may have extra expenses each month that you can cut out. If you could cut those, how many books could you buy?"
I love reading books, so I become a little interested. Since then, I have been managing my money diligently.
For adults with Asperger Syndrome, instead of forcing them to do something that they are not interested in or not good at, try telling them the merits or what they can get out of doing that something.