Certainly my chosen special interests are my main strengths. Mainly it's music, particularly singing and making recordings, also any kind of sound/video technology.
I don't consider myself "truly great" at them - my areas of expertise tend to be very limited, so for example I know a lot about my own methods of recording engineering but would be quickly identified as useless in a commercial studio because my skills would be too narrow. I've more sussed out the techniques that work for me, and I've done that very thoroughly, often using obselete equipment and unconventional approaches to make a silk purse out of a sow's ear.
I've had lots of compliments about my singing, though my perfectionism always reminds me of the shortfalls - if I could just accept that I'm a baritone then I'd probably be content and proud of my work, but I always envy tenors because they can get higher notes than I can, and basses because they can get lower notes. I think nothing of doing fifty retakes of a vocal part, chasing some holy grail that nobody else would even notice I hadn't got.
I like science as well, and have a science job, but it bores me unless I can see how I might apply it to solve my own problems. I know it brings the money in, but somehow that's too far removed from the really serious business of working on my music - even if it allows me to buy good equipment, in a way I'd be happier working with cheap gear. So when doing my science job, the feedback suggests I'm very good at a lot of the things I do, and I usually apply my perfectionism to the task in hand, but I've never really fallen in love with it, because for me there are higher things to do, so my range of workplace skills is limited and I'm too apathetic to want to add any more new ones than I need to just hold onto the job.