I get my best ideas while I'm
i. taking a shower
ii. laying in bed in the total darkness of my room
And I solve problems
iii. when I don't concentrate on finding the solution.
I suppose due to my Fe in the auxillary place I can tolerate social gatherings and dinners and whatnot as long as they don't happen too often. I know when I'm drained, though.
I only
need alone time when I feel drained. Otherwise it's simply a preference. Well, inherently I am both social and a loner -- I can't really function without loved ones and friends, and I can be affectionate too -- but more of the latter.
Generally I get along with people. I've never held a grudge in my life. In real life I could be characterized as happy-go-lucky to an extent, and rather serious to another extent. But mostly I'm calm and a silent fellow. I am also shy and I suck at eye contact especially with females I find attractive in some way, as I generally avert my eyes just as they meet, see my signature. Recently found out that alcohol helps.

(Yeah, I have no girlfriend. Sue me!)
I'm not quite sure about what stimulates me. I definitely like reading a lot, and have a preference for fiction. I can devour any book if I find it stimulating or engaging enough. I also spend a lot of my free time reading Wikipedia in a fairly passive sort of way, you could say that I maintain this ever-existing, passive curiosity towards the world. Often it manifests in ambivalence -- I can't say I'm passionate about a great deal of things. I like introspection and especially looking at things from perspectives I hadn't thought of before. Reading, and to a lesser extent, social interaction and observation helps achieve these new perspectives. I used to frown at myself for being so reliant on these factors to cause these shifts in view -- then I realized that's just how things work. See, there's an example!
Generally though my self-esteem isn't high. Speaking a bit more specifically as an IN, I
can't live the moment. (though alcohol helps here too!). I am also a bit of an underachiever (according to external sources, of course) at my high school with no favourte or disliked subjects -- due to the aforementioned ambivalence, I don't really spend any time on schoolwork, and so far I've found that nothing really engages me very much, regardless of the difficulty. (it is not the case that I breeze through everything) I just felt like mentioning it as it probably has ties to the natural self-absorption of most introverts.
This was fun. Hope it's been informative.