Earlier quoted context omitted.
This is the poster example I use for how dramatically information can change within our lifetime. I still encounter people that are unaware that most of the "stress causes ulcers" was just wrong.
It certainly matters more in medicine, where you have very serious risk of causing people pain, but as I've gotten a bit older I've become a lot more sympathetic to people having trouble keeping up with the world sometimes. Like, it's not a good excuse, don't get me wrong, but as much as I try, I simply cannot keep up with the entire state of the art of computer science. I wish I could, and a younger me without a fam…
This is the part of this conversation that I don't get. Yes, it is impossible for one person to contain the entire body of knowledge, which means you're not going to know some of the time, and that might be embarrassing or otherwise troublesome.
However... it should be rare that you operate in complete isolation. You should be regularly interacting with other practitioners, including people whose entry into the field is newer, and therefore should be aware of the current state of the art. There should be interactions where that information is shared, both allowing projects you work on to take advantage of advances in the state of the art even if you don't know about it, and for you to become aware of advances in the state of the art.