As you learned in the previous lesson your brain loses its focus and doesn’t remember very well when it is bored.
The rote memory method is boring because it makes your brain review the same words and definitions over and over and over which causes your brain to lose focus and start to wander.
The “define it and connect it” technique, is more interesting than rote memory and connects the meaning of the word with what it looks like and sounds like which improves your memory greatly.