I've worked in service industries (of which I'll lump in TSA and Customs officials for now) and have been on the receiving end of it, polite or cordial people are welcome to talk about their experience, but then you get people like a friend of mine that would rather make them feel miserable about what they do for a living (the reason I can only take him in small doses these days).
What specifically does your friend do to piss you off?
With the TSA he likes to derail the process (unless he's short on time). Not just asking for a pat down rather than the scanner (if I gave myself more time at the airport I'd likely do the same), but to the point of abusing the worker rather than making the system itself slow down. Also, he has little regard for those behind him in line, and doesn't mind delaying them a few minutes so he can feel better about himself.
As I haven't spent much time with him (physically parted ways after college) the past few years I can't really recall any more specific incidents, but it was a reason that, in college, it took us about 6 months to become friends. I thought he was a jerk, and I was right, he just happens to be a good friend as well.
There have been people like jasonkester that have appeared in my life before. When times have been good they didn't inspire me, but were just good fun. When times have been bad, their example pushed and motivated me to get my life back on track. They may never have known what kind of good they did for me, and they may have even departed from my life, but I'm extremely grateful for the time they spent with me.
I really don't want to wear the same t-shirt for 40 days in a rainforest, and I really don't want to emulate jasonkester's travel plans; I'm allergic to spiders and nature! However, if I got stuck stamping passports or asking whether you'd like fries with that, I'm quite sure his passion would be quite invaluable as a reminder to sort my life out.
What jasonkester did can be done unpleasantly. Nobody likes people that say "nah nah nah nah boo boo my life is better than yours!", but I just don't get the feeling that's how it went down in this instance.