I work too hard for my own good sometimes and it gets bad sometimes when I go for a few days without much sleep.
I like intelligent conversation (huge turn on*, especially if it involves crazy probability and PDE math and self-adaptive control systems or even philosophical discussions), outdoors activities, and crazy-smart people.
Most 'smart' people tend to be condescending and I find that annoying. I graduated within the top 2% of my class with a Bs and Ms in mechanical engineering and I still think that anybody can understand anything I'm working on or thinking about, so using the excuse that you or 'they' are not smart enough to get it is a silly excuse of someone who doesn't know what they're talking about.
I laugh a lot. I giggle a lot. I smile a lot.
Most people think I'm too happy, but I just try to be pleasant around others instead of being grumpy.
This pretty much sums up the way I live my life: http://www.youtube.com/watch?v=SuPLxQD4akQ
* I'm probably sapiosexual.... not enough evidence to prove it statistically, yet.