Everything military is a good example. Who doesn't like the idea of working on secret, state of the art technology? Truth is, the secret part mostly gets in the way, because of the "right to know", you don't really know what you are working on, and you may not even have internet access on your computer. As for the "state of the art", it tends to be pretty underwhelming. Besides military-specific constraints like stealth, it tends to lag behind civilian technology, probably related to the already mentioned secrecy that gets in the way.

Same thing happen when you get to work with really expensive equipment. Sounds great because who doesn't want a machine almost no one can afford? In reality, you are unlikely to get to play with it. Because it is an expensive machine, your company is going to make sure it is used to make money and not just for your own curiosity. Personal use is likely to get you fired.

I have to go get a car battery replaced, but when I come back, I'll share a few tales.

Sometimes, I would stare into the Reactor Compartment through the glass (there's a large-ish - around 6" - 8" if I recall correctly) porthole that allows you to look right into the reactor compartment at the nuclear reactor. I never stared for long... maybe 5-10 seconds at most, but staring at nuclear fission occurring is truly an awesome experience.

There's no Cherenkov radiation emitted, so you're just staring through glass at a bunch of metal, but you still know its occurring... and that was enough for me.