I had a pretty good buddy who was a retired helicopter pilot in the Marines, and he, many times, told me there are 4 groups of helicopter pilots that most people fit into. I think that there are strong parallels in software dev (and other fields!) and it might be useful to chat about here. One thing to note is that through training people can move between these categories, nothing is permanent. I think if you look at any of these groups from the perspective of "would I hire this person?" the answer is a "yes, but..." where we need to be very aware of the person's limitations and groupings
1. Pilots who are good and they know it. These are people who are naturally good pilots: memorizing the checklists, failure states, what to do in bad conditions, etc come very naturally to these people and they don't need a lot of training or hand holding. Generally great to work with unless they are cocky.
2. Pilots who are good and they don't know it. Pilots in this category have everything going on from the first category, except they don't realize how good they are. Often times, these can be the best pilots to work with, because they stick to all the checklists, procedures, manuals, policies, and so on, because they know that they might not know what they are doing, and on top of that they can shine in tough situations because they are in fact good pilots. These pilots are great because it's very rare to get one with a lot of ego.
3. Pilots who are bad and they know it. These are people who are aware that they are not naturally strong pilots, and their awareness leads them to following checklists, spending lots of time reading manuals, procedures, policies, to a T. In most situations, these are very good pilots to work with because they are aware of their own limitations although they may need more training for bad situations. Again, there is often very little ego here. I think this is the level of awareness that we're seeing in the OP here.
4. Pilots who are bad and they don't know it. This is the worst group of pilots to work with, but they can be fixed with training and guidance from senior pilots. Often times if you asked a pilot in this group, which group they fit into, they would tell you they fall into the "good and know it group", but they're wrong: they might be skipping checklist items, missing key policies, or just generally be a bad team mate. I would liken this to a junior or mid level dev who thinks they know everything. Often times there can be a lot of ego in this group