Putting aside dangerously wierd stuff, I would say probably my sense of humour. It's completely different to everyone i know and i pretty much laugh at nothing my friends laugh at (resulting in them claiming i find nothing funny) but my sense of humour revolves around completley out of place events. For example if i ever have to create a powerpoint on anything, i HAVE to add in custom animations invovling the title of the slide to spaz around the slide expanding/shrinking rapidly, inevitably resulting in me sabotaging my presentaton as im left there laughing at my nonsense.
The only reason why others laugh is because my laugh is also pretty wierd but that's besides the point.
I also find darker things funny. for example i cant help but laugh when i describe spontaneous combustion. People think i like the thought of others dying but it's actually just the thought of having a nice normal day and then out of nowhere.... youre on fire!!! No source, no reason, you're just burning!
TL;DR my sense of humour, it's ridiculous and i wish it was changed but i still like it. People get wrong ideas from it