Because you feel this way during baseline, it could simply just be your personality (high in extraversion, most likely), which is generally stable across the lifespan. Based on your description of yourself, you are above average in both intelligence and attractiveness. Because you were repeatedly positively reinforced about these particular qualities (e.g., high grades in school, dating objectively attractive men), it's possible that over time, you may have come to attribute these qualities in yourself as part of your self-worth. If so, this would be a possible explanation for your need for reassurance during depressed episodes, since depression creates all that nasty self-doubt and negative self-talk, even when we don't realize it's happening.

When I've been hypomanic, I very much believe that I am much smarter and more attractive than everyone around me, and like one of the above posters, go on rants about how "stupid people are." However, I have also been repeatedly positively reinforced by others about both my academic achievements and attractiveness, regardless of my mental state, though I don't believe a single word of it when I'm depressed.

When I'm depressed, I feel disgusting, ugly, feel like I haven't "achieved enough," and I tend to seek out comparisons of how I'm intellectually inferior to person X or Y to "prove" or "validate" these distorted negative thoughts, even though objective evidence (i.e., grades, awards, accolades) says otherwise. I honestly have no clue as to my "baseline," because in retrospect, I only have been able to identify my extremes.

Overall, I'd guess it is possibly a combination of your personality, objective truths about yourself, positive reinforcement about those qualities, and possibly some bipolar grandiose thinking. I guess what would tell you the most about it being bipolar related is if you or others notice a marked increase in these feelings of superiority when you're hypomanic or manic. Might be something to explore with your therapist, especially if it's something that bothers you. At the very least, you're not alone in these types of thoughts. Hope that helps...