That I really don't matter in the grand scheme of things. A hundred years from now no one will know my name or recognize my face. Any and everything I do will disappear when I die. Part of it will live on in my children maybe a bit in their children then after that I'm gone. There have been billions of people that live and die without ever being known by more than a few. Hell when you take a step back from that we get even smaller. So yeah I find it scary that I don't matter in the big picture.

That my complete lack of social skills might lead me to never get a job or a life outside of my room.

What terrifies you /u/septimine? :)

For me, it would have to be an intruder or some sort of home break-in. To go broader, I would say people in general. I'm not sure when this struck a chord with me, but I'm just absolutely horrified of someone breaking in to my home. When coming home from work or class late at night, I would walk very briskly from my car to my apartment. Any sort of noise disturbance (people talking in the distance, a branch snaps) also really freaks me out at night.

Leaving a club downtown and not remembering where I parked.

On an everyday scale, im deadly afraid of spiders.

Im also terrified of the deep ocean to the extent that I can barely paddle at the beach anymore (for fear of krakens, of course)