So the question is not to learn or to know the concept of what is allin! it is the experience of knowing when to use it, it applies to all the jargon you can learn related to gambling.
Also we need to know the term first or their definition before we apply them as that can make things easier. From my long time of stay here, I already learned a lot of gambling terms but I didn't apply the others because they are from a different category, it was from sports betting already and I am not really a fan of it.
I do not understand, the counter question on your part, even more so when you give yourself the answer based on your thinking, when in my post I gave my point of view. There is the answer.
I never said "it's embarrassing, it is difficult to learn, etc" don't put me in your words. By the way and it is worth saying, there is nothing wrong with your answer, but it is your opinion not mine.
There is nothing embarrassing, or anything learning, we must bear in mind that your jargon may not be mine in all the scope of concepts that exist, that is the point that makes it individual / personal, my specialty is poker and I remember that one of the first concepts I learned was the implicit odds (if you don't know what it is, there is no problem GS) some time later I read that one of the best poker players someone asked him about it and he replied that he did not know what they were talking about, when they explained the concept to him he understood what they were referring to.
Now if you understand the point (!?), in that particular case he has stated that he is an empirical player and not influenced by concepts, readings, specialized techniques, but he knew the concept , so his learning was different, that player is Phil Ivey.
Who by the way at 2003 in a curious interview he mentioned something like "... I didn't know much about holdem": https://www.youtube.com/watch?v=5NXzafZfQjw