My mask of sanity is about to slip.

I don't really know why but I've recently noticed something rather odd about myself. I'm not sure if it's odd or if it's something that everyone does but never speaks of for fear of being accused of insanity by other people who secretly do the very same thing. I've noticed that when I'm in public I tend to imagine these very detailed hypothetical situations and all their possible consequences that usually have an unpleasant or maybe even bloody conclusion. Examples:

• When I'm walking down the steep and very crowded metro stairs, I always wonder what will happen if I slip and fall on the hard cement below, breaking my jaw with blood spraying a metre in front of me. I guess some ppl will try to help, someone will likely steal my wallet and phone from my bag and others will simply try to quickly avoid the sudden crowd and continue to their destinations after taking a small glance at the cause of all the commotion. Most people though will probably just gather around to watch so they could tell their friends and families all about it because we just love to watch horrible things happen to strangers and then use them for small talk.
  
• I would then feel a sudden disgust and imagine what would happen if I pushed someone.
• Sometimes when I'm especially pissed off, I walk around simply looking hostile and daring anyone to say or do something stupid, so that I can take it all out on a stranger I'll never see again but get the satisfaction that I just made the day a little gloomier for someone I don't give a shit about and probably hated on sight.
  
• When getting out of a car or a taxi with a friend, I wonder what might happen if that friend gets a little too enthusiastic about arriving and slams the door in my face while I'm still half way out.
  
• Then I wonder what might happen if I do it.
• When I have close calls, like almost slipping on the stairs or almost getting hit by a vehicle of some sort, I never let it just pass. I have to imagine the possible consequences up to the point where I'm lying in a hospital bed unconsious with my family and friends standing around me and looking sad.
  
• I imagine if they actually will be upset , or how long it'll take my friends to notice that I'm gone and then how long it'll take for them to forget me.
  
• I wonder what will happen if I tell that "acquaintance" talking to me while I'm smiling at her that in reality I can't stand her guts and want to give her a good slap or two on the face because I know she secretly hates me for whatever reason.
  
• Sometimes when I'm out with my friends, walking around with the ever present water bottle in my hand just laughing and having a good time, I look at complete strangers and wonder what might happen if I bang them on the head with said bottle. An outrage I bet! My friends looking horrified at me, me with a twisted sick smile on my face, my victim looking at me speechless and ready to throttle me at the same time
• I often wonder what will happen if I shout an expletive at that smug, arrogant, misogynistic professor in the middle of class just to see the look on his face. He'll probably make sure I never graduate and ruin my future because I'm a worthless kid who decided to let him know that he's an ass.
  
• Right now I'm wondering what kind of impression do I hope to give by quoting American Psycho in the Goddamn title .
  

I choose to believe that this is all a normal part of having an overactive imagintion. Reassurances of this theory are more than welcome