Flourescent lighting
It's driving me absolutely fucking nuts. One of the flourescent lights in the bathroom has reached the end of its life-span and is doing things that only those stupid lights do. Other lightbulbs just go off and stay off, these damn things keep on flickering as if they were a twitching corpse that has no chance of coming back to life but still keeps going at it. When it's day time I tend not to notice, as daylight coming through the window provides me with enough lighting to do whatever it is I went in to do. It's at night time that it kills me, as I go about my business expecting the struggling light to come on at any second. And then I remember that it never will. This causes me to have to complete what I'm trying to do using a manic, psychotic slow motion kind of strobe lighting.
The thing is, there are two switches, one that turns on the fucked up light and one that turns on a perfectly normal light. By sheer force of habit, I ALWAYS turn on the busted one. This is a habit that is rooted back into the days where I spent most of my time at home, probably all the way back when we moved into this house around 14 years ago. Every damn time, I always get frustrated and remind myself to switch on the other light, but it never ever works. I just stand there like an idiot in the darkness waiting for the momentary flash that allows me to kind of get my bearings straight.