The more you WANT something to be true, the more you work to show it isn't true.

Many times I have come up with an idea that would benifit me greatly in the work I was doing... after the initial excitement I sit down and ruthlessly try to show it cant work- usually I find it can work but just isn't practical... other times I find it's physically impossible once you look at the physics, but on the occasions where its practical AND possible it turns out to be a real gem... saves a project 10's of thousands, reduces downtime, makes a task easier, increases safety, allows a new discovery etc...

Scientists know the danger of wishful thinking...