Some LSAT students fail to learn quantifiers. No one who fails to learn quantifiers has mastered the LSAT.
If you’re scared already, fear not. It’s worth knowing your way around some, most, and all statements and the inferences you can and can’t draw from them. And while it’s worth just memorizing what you can and can’t do with quantifiers, it’ll be easier to memorize the valid inferences if you understand how they work.