I am an easily frightened person. By that, I don't mean that I'm scared by monsters and whatnot... I'm just easily frightened by unexpected circumstances.
It's gotten worse over time, not better like I'd expect. A loud noise, someone suddenly entering a room, a telephone call- it can be anything. And I don't just jump a little bit, I scream. Loud.
My mom owns a candle shop. Sometimes I'll watch it while she's out. I'll be sitting at the computer or whatever, and someone can just open the door to browse around the store, and I'll scream my head off, simply because I didn't expect them to come through the door.
Last night my mom was picking me up, and as I went to open the front door of the car, she said "Get in the back". I screamed. I guess the only reason why I screamed is because I wasn't expecting her to say anything, or something.
I haven't actually had this problem a long time, maybe only a couple years. It is embarrassing when someone gives me that "What the heck is wrong with you?" look. And replying "It happens a lot" doesn't seem to make the matter any better.