Bad mood bitching

My back is hurting. All the driving is taking its toll I guess. So, I take this unique opportunity to bitch against people who take me for granted. I hope I am mistaken, and there are genuine reasons for people behaving like they do, but the bottom line is I am pissed by people who take me for granted. Be it my time, my acceptance of mediocre behaviour, my patience, my help and things like that.
Case 1:
I don't like waiting. Irrespective of what pathetic a use I put my time to (when I am not waiting), I don't want to spend it waiting. Today, at 12:30 in the noon, I waited for a student who made an appointment with me to discuss some homework assignment, and did not show up. Not only did he not show up, he did not apologize when I met him in the class later. The cheek really!
It makes me think.....Was he so self-obsessed that it did not occur to him at all? I am pretty self obsessed myself but, I try to control the damages of my self-obsession affect very few people. Okay one people. My husband. So, I wonder.. what was he thinking.. Did he really think that he did me a favor by asking for my help? Just because I grin more often than necessary in the class, does it mean I will lap up any offer of contact with my oh-so-precious students? Did he think that he can get away with it, since I am so distant that I will not be forthright in expressing my discontent?What is it?
Case 2:
Also, I do not like people who think that since, I am generally nice, I will be quiet to any unfairness. One of my acquaintances just made a decision on my behalf and refused to acknowledge that I was left holding the sack and that what was done was unfair. So much so that I had to nudge, then ask and then fight about it. Since I have an inertia against raising hell in confrontational situations, people think I can be herded to any damn cowshed. Is it that people think any unfairness is OK as long as some one does not pull the corpse into the sun?
What is it?
Case 3, 4, 5,,, STOP:
I also hate people who basically expect help without even making the slightest of efforts to do things themselves. Add to that, people who will just assume that you are going to listen to hours of how bad their life is because they have only a 35 K and fully loaded BMW 3 series is above their reach. Worst are the people who think they are being cute when they ask help.. oh let us not even go there... My head is going to explode and the fountain of plasma will burn through my couch... We don't want that when our backs are hurting and our butts weep at the mention of hard-backed chairs... do we?

Although, at more level headed times, I tell myself that I should give people the benefit of doubt. I cannot possibly be objective in judging people, since I cannot really get inside their heads and read their preoccupations. Also, most of the times, I cannot tell off people because,... I don't know.. May be I am a chicken, or perhaps, I think I should not jeopardize my relations due to petty incidents. But, at the same time, I also wonder, how is it that such things as courtesy, fairness, and responsibility to commitments, etc. do not occur to people by nature. I don't know!! I am angry! I am angry because people are screwing with me.. and I am angry at myself at being so angry!