Learn as if You're at Har Sinai
You are not liable for forgetting your learning unless you actively forget it. Forgetting doesn't only mean completely forgetting, it also means if something doesn't make an impression on you.
Doing things that promote forgetfulness, not reviewing what you learn.
Ma'amad Har Sinai was an unforgettable experience. The Ramban says that if we learn in such a way that we feel like we are learning it at Har Sinai we won't forget it. If you forget it, it's because you didn't learn it with enough intensity.
Delivered at the OU Israel Center, May 20th, 2019, 15 Iyyar 5779