Seems to me that you want to be ambitious, but not crazy. The proposed project must be well within the constrains of reality - must be a hypothesis that can be actually tested that is - and must not ignore decades of well-established facts, just to foster some lunatic, crazy-ass idea that one may have. 
 
The flip side to this is that there will be the occasional crazy idea that will be correct (prions come to mind right now, but science is littered with them - viruses causing cancer is another). Probably a simple rule of thumb is that  imagination needs to be based on reality, and must be eventually verified by real experiments!

As I was walking to my car a few days back, I saw a pickup truck parked with the back of a (brand new) chair sticking out. From where I was, I only had a sideways view of the truck, and I could also see the base of a (also brand new) chair sticking out (the ones that have swiveling wheels), but it was clear (to me) that the back and the base did not belong to the same chair, as they were not together.

So from 30 feet away I made a swift judgement. This guy transports chairs, and he has at least two chairs in his truck. I had all kinds of visions of the office that he was a contractor for - one with at least two chairs and a desk. As I got nearer, I could now see the truckbed clearly. Both parts belonged to the same chair, but for some inexplicable reason this dude had separated the base and the back of a brand new chair and was transporting both in his truck.
 
Nevertheless I was reminded of the extreme importance of forcing the mind to formulate alternate hypotheses for every possible scenario (as a scientist), and the value (as a physician) for always having a list of differential diagnoses. My absolute belief that there had to be at least two chairs prevented me from even considering that both the back and the base could possibly be part of the same chair. Hope that guy found a way to put that chair together!

Bruce Springsteen predicted the coming of social media decades ago...57 channels and nothing on... thankfully we have youtube, so I can make everyone aware of my view on this topic :)