Our memory of exact word sequences usually fades more quickly than our memory of (contextually interpreted) meanings.
More broadly, the exact auditory sensations normally fade very quickly; the corresponding word sequences fade a bit more slowly; and the interpreted meanings last longest.
These generalizations can be overcome to some extent if the sound or the text has especially memorable characteristics. (And the question of what "memorable" means in this context is interesting.)
On the surface, the world of agile software development is bright, since it is now mainstream. But the reality is troubling, because much of what is done is faux-agile, disregarding agile's values and principles. The three main challenges we should focus on are: fighting the Agile Industrial Complex and its habit of imposing process upon teams, raising the importance of technical excellence, and organizing our teams around products (rather than projects).
It actually doesn't matter whether you actually have a formal retrospective. It doesn't matter whether you have four or five labels of things on your retro board, or exactly how you do the retro. What does matter is the notion of thinking about what we're doing and how we can do better, and it is the team that's doing the work that does this, that is the central thing.
Interestingly, just as software people were talking about how we need to kind of follow this very Taylorist notion as the future of software development, the manufacturing world was moving away from it. The whole notion of what was going on in a lot in manufacturing places was the people doing the work need to have much more of a say in this because they actually see what's happening.