I've always been a bit of a "knob'er". I like to twist anything with knobs. I work in IT and electronics have always held my interest. That's one side of it I guess. The other is having grown up in West Texas, I've seen the power and destructive capabilities of foul weather. Skywarn and ARES are two of the major weather spotting groups associated with NOAA and use ham radios to communicate. Also, in addition to that, I was a Boy Scout and learned to 'always be prepared'. Land lines and cell phones won't always work (see Katrina) and there will always be a need to send and receive messages.
The field day is sort of a show off day for Ham Radio. There are contests and demonstrations, and in our group a lot of camaraderie. We set up where cell phones don't work (up in the mountains west of Denver), and show just what kind of capabilities we still have to communicate. Phone patches (radio to land line), internet (packet radio), and other forms of communication all take place during the weekend.
Hope this explains it a bit.