I did one of these tests and I was labelled an extreme systemiser. I had a very high systemising score and a really low empathy score which worried me for a while. But then I realised I may just be a very natural scientist! (I should be considering I'm studying for a masters in Pharmacy)>
anyway my interests are highly eclectic. I know an unbelievable amount about music (Artists, genres, periods of music, structure, songwriting etc), I also know a silly amount about psychiatry, psychology, pharmaceuticals, biochemistry and biomedicine. (and a lot of them aren't due to my degree but are out of my own personal interest.
I also know a lot about literature, history, aviation, politics, space flight and countless other things.
Most of my interests besides music and literature are extremely scientific and I often find myself engulfed in data, journals, research papers, scientific american and similar magazines and on wikipedia learning all I can about things like genetic disorders, psychiatric disorders, treatment methods, differential diagnoses, the epidemiology of disease etc etc etc etc
It's only recently I've learnt that I'm definitely an aspie although I'm not diagnosed. I had an assessment and met a lot of the criteria for someone with aspergers but they wanted to interview my parents and I wasn't happy with that.
To think at one point I used to think being interested in so many things was a normal trait!