Note that when I say 95%-ile, I mean 95%-ile among people who participate, not all people (for many activities, just doing it at all makes you 99%-ile or above across all people). I'm also not referring to 95%-ile among people who practice regularly. The "one weird trick" is that, for a lot of activities, being something like 10%-ile among people who practice can make you something like 90%-ile or 99%-ile among people who participate.
Relatively few people obsessively try to improve and figure out what works, which results in a lack of rigorous curricula for improving. However, this also means that it's easy to improve in percentile terms since relatively few people are trying to improve at all.
At one of the first conferences she spoke at, the night before the conference, we talked to another speaker who mentioned that they hadn't finished their talk yet and only had fifteen minutes of material (for a forty minute talk). They were trying to figure out how to fill the rest of the time. That kind of preparation isn't unusual and the vast majority of talks prepared like that aren't great.
One thing to note here is that it's important to actually track what you're doing and not just guess at what you're doing. When I've recorded what people do and compare it to what they think they're doing, these are often quite different. It would generally be considered absurd to operate a complex software system without metrics or tracing, but it's normal to operate yourself without metrics or tracing, even though you're much more complex and harder to understand than the software you work on.
Anyway, this is sort of an odd post for me to write since I think that culturally, we care a bit too much about productivity in the U.S., especially in places I've lived recently (NYC & SF). But at a personal level, higher productivity doing work or chores doesn't have to be converted into more work or chores, it can also be converted into more vacation time or more time doing whatever you value.