I, for one, almost never talk about my special interests or even obsessions. Not as a child, not as a teen and still not as an adult.
Whether or not I was socially aware that it bores others (unlikely actually), I'd rather keep it to myself.
Not because I was 'shy', it's because I seriously just prefer keeping things to myself than spreading it around no matter how great and and awesome it is.
If it just comes to special interests, I just don't usually do words. I don't spout words, I don't hoard terms...
In certain interests, I can limit myself to that because it's all my time and resources can grant me.
Got the same usual itch and intrusions, but not the same expressions.
As for any new urges to dig in different directions that came along with time; I barely got a new one since around 2 years ago or so.
Sometimes my life long special interests just halt for months end -- it's driving me into boredom.
Yet I sort of figured why any obsessive urge hadn't come to me; it's not because I've been more repressive or apathetic, it's because I've been running empty. If I wasn't mentally exhausted in some ways, I get certain ideas in my head that are intense, can lasts, and can wisely implemented.
This certain fatigue can disable the autistic urge to focus and stay there -- even a narrow or a rigid one. One of the reasons why I want this case of mine fixed.