One of the reasons people might be fallible, why we might fail to do what we try to do isignorance, that we have a limited understanding of the laws of the world - the physical laws that govern the world and of all the particulars of the world upon which those laws work. And then there's ineptitude, meaning that the knowledge is available, but individuals fail to apply it correctly. The third source is "necessary fallibility." That is, we're never going to be omniscient, there is some knowledge that we will simply never achieve, and there are limits to what we will be able to do.

Man is fallible, but maybe men are less so.

Go back to the '30s, '40s, '50s, and it was the discovery of heroic interventions, the ability to cure people with penicillin or do an operation to stop disease that was what saved the day. Primary care physicians couldn't do all that much that really demonstrated a difference. The people who control and work with you to control your blood pressure, they're not rewarded for doing that or to be innovative about doing that. So, the result is half of Americans have uncontrolled high blood pressure, despite seeing clinicians.

We always hope for the easy fix: the one simple change that will erase a problem in a stroke. But few things in life work this way. Instead, success requires making a hundred small steps go right - one after the other, no slipups, no goofs, everyone pitching in.

Just look at the list of who the lowest-paid people are. Pediatricians are at the bottom. You would also look at internists. You would look at psychiatrists. You would look at family physicians, HIV specialists. People who take care of chronic illnesses by seeing people carefully over time, those are the people who get the least money. The people who have the most are people like orthopedic surgeons, interventional cardiologists. And my point isn't that there is something wrong with heroism.

Good checklists, on the other hand are precise. They are efficient, to the point, and easy to use even in the most difficult situations. They do not try to spell out everything--a checklist cannot fly a plane. Instead, they provide reminders of only the most critical and important steps--the ones that even the highly skilled professional using them could miss. Good checklists are, above all, practical.

Practice is funny that way. For days and days, you make out only the fragments of what to do. And then one day you've got the thing whole. Conscious learning becomes unconscious knowledge, and you cannot say precisely how.