One of my favorite t-shirts has a phrase on the front of it:
“Teach everything you know.”
It’s good life advice, but it’s good student advice, too:
If you want to really see if you know something, try teaching it to someone else.
Not only will you learn it better as you intend to organize the information to teach it, as you teach you’ll recognize gaps in your knowledge that you can then go back and fill in.
Give it a shot and teach what you know!