OT: That was easily the hardest lesson to instill in my math students, and the most impactful once internalized. Being comfortable experimenting with ideas you don't yet fully understand is critical to the learning process.
i think people in general can often have too much of a move fast and break things attitude, and i tend to be the opposite, but my default tendency toward risk aversion can definitely go to far. balance is important.
i think explicitly reminding myself to think about the realistic cost of failure can be helpful. e.g. 15 minutes or an hour starting in an uncertain approach to implementing a software feature, or writing something, or trying to sketch out a proof probably isn't a huge deal. 15 minutes or an hour trying some novel approach to fixing a production bug that's writing bad data when there's some known tedious thing that'd staunch the bleeding in a few minutes, or sinking many hours and/or much money into an uncertain hobby or activity, those might be less worth the risk =) (but i didn't get the impression you were including that sort of thing, just rambling)