Whoops. Well to a certain extent you might not be able to feel fun in a in-the-moment way like some other people...you're already showing boredom in certain social things. There are a bunch of times where I socialize just great but don't remember any of the conversation later. I guess you can't expect yourself to derive fun from social things...if it's any help, what I usually do is, I talk more to people who are interesting to me for whatever reason: intellect, personality, they do something neat like breakdance or basketweave. I have fun when I'm curious. My mind is also staying active when I'm trying (not straining, though) to come up with things to say, based off of what's being said in the conversation. I immerse myself socially in a way that suits me. And another thing, you're bound to get bored if you remember what you're thinking. In other words...don't think about what you're thinking. If you've gotta think...think about what's going on...if you're in the middle of a conversation, if there's one you should jump into...
However, if you can find a way to watch a movie without internal interruption then please tell me. I love to watch movies, but I have a problem with drifting in thought while watching, especially if I'm ALONE or in a bad mood.
Hope I gave what you were looking for!