In roles where individuals have a lot of responsibility (e.g. the direct protection of others) how can the idea of a 'learning curve' be tolerated? It seems to me that there are always situations in which people, like doctors or soldiers, must make judgement calls, but if such decisions - though rational and educated - don't achieve the desired outcome (e.g a patient dies, a fellow soldier is put in harm's way), how can the decision makers tolerate having made them? Are there certain roles (like being an emergency room doctor or president) in which the individual filling that role has to accept that despite their best efforts they are very likely to cause others harm or to contribute to it? Is that a risk that just goes with the job?