Coping mechanisms to social alienation

For much of my life, I've felt very alienated. Talking to other people always felt like a chore or inconvenience. I rarely have a conversation in which I can relate, but in social surroundings, I'm compelled to add to the conversation. The majority of what I say in groups of people are careless ramblings. I feel as that's my way of entertaining myself. I often find myself in situations where things are so dull I feel I need to do something disruptive in order to make the drudgery bearable. People often think I'm hungry for attention and view me as somewhat of a clown when in reality I'm not trying to get anyone's attention; I'm trying to keep myself from going brain dead. I feel as though many classmates of mine view me as the guy whose always trying to be funny, causing them to disregard anything that comes out of my mouth. But when I actually feel the need to discuss what's truly on my mind, the people around me are always surprised by any amount of intelligence that they become so awe-struck that they don't even take what I say seriously. This led me to believe that this process started because of nobody really understanding what was on my mind in the first place, so at some point in my life I developed a way of coping with other people's lack of understanding. Now before you all think I have a superiority complex, I'm speaking of my actions in groups in which I don't truly relate to. (Mostly classmates. People who don't actually know the "real" me.) In my friend group however, I always have a strong need to speak my mind and engage in intellectual discussion. In classes where I don't have any friend to talk to, I always get trapped in some kind of complex thought while being able to process whatever we're learning. But if I get called on to answer anything, I'll sit there for an awkward few seconds and not be able to answer a simple question, as if I can't snap back to reality. It's annoying because this only reinforces everyone's idea of me being an unintelligent pothead when I know I was constructing ideas in my head that nobody in the room could even comprehend. Does anyone feel this way or have a similar way of dealing with misunderstanding? And do your coping mechanisms (Acting like a fool in large public groups/focusing all your attention towards personal thoughts in awkward surroundings) lead others to believe that you're unintelligent?

-Sorry for the rant.