Everyone has a fact they have looked up a dozen times and still cannot hold. The problem is almost never the fact — it is that reading something is not the same as retrieving it, and only retrieval builds memory you can use under pressure.
Reading is not remembering
Looking a fact up feels productive because it resolves the discomfort of not knowing. But recognition is far easier than recall, so a fact you have read ten times can still be unavailable when somebody asks you directly. The test is simple: close the page and say the answer out loud. If you cannot, you have not learned it yet, however familiar it looked.
Space the repetitions
Memory for something new decays fast at first, then slows. Each time you successfully retrieve it just as it is fading, the decay flattens — a week becomes a month becomes a year. In practice that means reviewing a fact tomorrow, then in three days, then next week, rather than staring at it five times tonight. Ten short reviews across a month beat an hour of cramming and take less total time.
Hook it onto something you already know
Isolated facts are the hardest to keep. A capital city attached to a river, a war, a football team or a friend’s holiday has four ways back into your memory instead of one. This is why quizzing is itself such an efficient way to learn: the wrong answers you hear stick to the right one, and the whole cluster comes back together next time.
The fastest gain for most people is simply to answer out loud before checking. It converts passive reading into retrieval, and retrieval is the only part that lasts.