I like finances, I like to work everything out. I note down almost everything I spend. I also work out how much each of my toiletries cost per month so I can see what is cheapest. I am quite careful with money and try and save as much of it as possible. I don't know if this has anything to do with Aspergers, it might just be because I am Scottish
Every now and then, I do overspend (by my standards). It's almost always during the early phase of a special interest. Then I get very anxious about it and feel awful.
I think your family should be glad that you are responsible with your finances, so many people get into debt unnecessarily.