Interesting that you chose geology, as I often think that I'd have been happier as a geologist. I imagine there's a risk of getting bored with that as well, if it's your day job and you're doing the same sort of rote work all the time. In my fantasy, the primary appeal is that it's almost the opposite of sitting at a desk, except I suspect most professional geologists spend most of their time sitting at a desk looking at data on a computer. Seems like a fun hobby though!