We're all about mastery!
The same approach you used to learn a new sport or musical instrument is what you'll find on FactSumo.
Practicing, little and often has a big impact.
Immediate corrective feedback gives you a chance to learn from your mistakes, and another chance to get it right.
Built-in study breaks let some forgetting set in, and expose what you "actually" know from what you "think" you know.
Seeing your progress builds your confidence and lets you see what's possible.