For us, in math and grammar, it is understanding and memorizing. For example, I do not concider addition mastered till the child can teach the concept back to me and give me the answer to a problem without any hesitation. This will bring about the kind of mastery you mention with the bead work. It will be easy to get back up to speed, if things become second nature now.
Now for content subjects things are different. I guess I don’t really look at these as mastery subjects, right now. If we do our timeline wall, weeks later, and my kids can give me the gist of what something was about, I consider it “mastered”. If they bring something up later on that we studied, I consider it “mastered”. If I see them playing something that we studied, I consider it “mastered”. But in reality true mastery is much, much more than that. If they understand the whys behind an event happening or how and why something works, plus have all the facts. That is true mastery. It is a mix of having complete facts and understanding, to have command of and to fully grasp a subject. I figure exposure will hopefully set off a light bulb, when they hear about the same things, later down the road. Then they will have more knowledge or understanding of a subject, but not real mastery. Now, if a child wants to go into a science or history field there will be things that need to be mastered as they get older. I don’t yet know if any of my children will be masters of these subjects. And even then it will not be of the whole subject. It will only be a subset or subsets of those subjects. Great question to ponder. Thanks for helping me think through that.