I am not a child psychologist, so take all of this with a grain of salt. I believe children first learn concepts by looking at and playing with concrete things first. "Oh look at this fun thing... Oh whoops I moved it, it looks slightly different, but if I rotate it, it looks like it used to... It doesn't really taste like anything, but it feels hard... Whoa, what's this new thing over here? Oh wait, this is the same size and shape as the thing I played with previously... In fact it behaves just like the first thing did. Oh cool, there's a whole stack of them over here, I bet they work just like the first things did!"
This is how one might interpret a baby's first interactions with blocks. Later in life, they might find out about dice and understand some similarities. Later, still in school, the kid learns about cubes in geometry class, and can think back to all the concrete hands on experience he had and see how the various principles of cubes apply in real life.
So, people learn by experiencing concrete things first, and then grouping all those experiences into abstract concepts. Sometimes (ok, often) they'll group them incorrectly:
Kid: "This thing doesn't have fur and moves without appendages. It's a snake. Whoa, look at this thing in the water, it moves without appendages either! It must also be a type of snake."
Teacher: "That's an eel, not a snake."
Kid: "oh. I guess snakes are for land and eels are for water"
Teacher: "Water Moccasin is a type of snake that is quite adept in the water."
Kid: "oh. They look kinda the same, what's the difference?"
Teacher: [performs instruction]
This form of learning by compiling all sorts of concrete things down into a few abstract concepts is so powerful and automatic that we do it ALL THE TIME. It can even work against us, "overtraining" to use an ML term, like with our various biases, stereotypes, typecasting of actors ("this guy can only ever do comedies"). Sometimes folks need a little help in defining/refining abstract concepts, and that's the point that teachers will be most helpful.
So, for me anyway, and I suspect many others, the best way to learn a concept is to get many (as different as possible) concrete examples, maybe a few concrete "looks like the same thing but isn't", and THEN explain the abstract concept and its principles.
Or, to explain the process without words, look at Picasso's first drawing of a dog, and the progressively shinier simpler drawings until he gets to a dog drawn with a single curvy line.