Stop copy-pasting. Start typing.
The keyboard is where understanding actually lands.
Copy-paste moves text. Typing moves it through you. That small friction, character by character, is where the understanding lands.
When you paste an answer you cannot adapt, you do not own it. When you type it, even slowly, you start to see the seams. You notice the part you do not understand, because your fingers slow down right where your head does.
So type the thing out. Yes, it is slower. That is the point. The reps are not in the reading, they are in the doing.