Just general decline in society, really. Lack of manners, lack of awareness, lack of politeness.

The number of people who can't grasp simple concepts to make everyone's life better irritate me, like not stopping randomly in fast moving sidewalk traffic so I don't walk straight into you.

I see the "step over the yellow line to right next to the carousel" all the time at airports, since I typically know when my bag is coming out and which direction the chute flows, it drives me nuts. I tend to lose all politeness about it.

Same thing goes at security though - I can get through security with 2 laptops & a backpack faster than people carrying only a handbag can.... why is that?