I don't even really like joining conversations much. People always just talk about stupid pointless shallow crap. I have no interest in whatsoever. And if you try to have a real conversation with some depth and knowledge they look at you like an alien. And most people can only relate what they saw on the news or whatever. I also can't stand that they always expect you to be like a stand up comedian with very word you say. It's like society has turned into real life sitcom talk where everything is some lame one liner. I can't stand it. Seems everyone knows a little bit about a lot of lame things. I'd rather talk about a lot of information about one thing at a time even.
The bolded parts of your quote are classic characteristics of more than one psychological quirk that a lot of us here have experience with. Neuroticism, poor self-image, projection come to mind specifically. The rest of your post is normal and is opinion off of real information (what they are actually saying) you are receiving during conversations.
Unless someone actually told you they expect you to "be like a standup comedian", then you are coming to that conclusion on your own, most likely as a way to avoid dealing with the fact that you don't connect with the people around you.
Maybe you are much more educated, have a higher IQ, and more advanced interests than everyone around you, so to you the conversations just seem like a waste of time?
On the flip side, maybe you have such low self-esteem, that you feel whenever you try to have a conversation with someone, they aren't interested in what you are saying. I can be in a very good conversation with someone, and be very interested in what they have to say, but not give any visual cues that would confirm that. If they were self-conscious, they could think I wasn't interested, or they weren't being funny enough, etc. How do you know that you haven't clammed-up/shut-down on someone before, when really they were enjoying the information/input that you were providing?
As to the first bolded point, what made you think they were looking at you strangely? Unless you had some spaghetti on your face or in your teeth from lunch, or you left your tie over your shoulder after you returned from the urinal (I have done this