Fixed isn't for me but I do love my singlespeed.
In my mind I do dread the hills a bit, but when I get to it the mindset kicks in and you know you have 2 choices: Pedal or walk. So you start cranking, and things get harder and you crank harder and get passed by a 50+ dude on a mtn bike (
happened last week on a big hill) But when I get to the top I get an immense feeling of accomplishment.
I guess to me there's just something kinda cool (masochistic perhaps) about knowing in your mind that you've got nothing but your legs and the only gear you've got to get you there. If things get tough, HTFU and pedal.
Its not like I wave it in other's faces or drop guys on 10 speeds while pointing to my single cog and laughing...but when i conquer a big hill or keep pace with the pack of superheroes I feel like an ass kicker.