The effortinvolved in writing a note in their own words, whichinstructional designers like to call a “desirable difficulty”helps shift the idea from short-term to long-termmemory (this is the same reason many note-makers areshifting back to hand-writing on cards rather thandepending on automated apps)

You might find that reviewing in Anki is harder than normal study. This means it’s working – Anki’s goal is to show you mostly the material you’re struggling with and the material you’re most likely to forget, so it will feel harder than an average study session where you study hard and easy material in more equal amounts. However, the difficulty and the number of cards you appear to be forgetting might make you feel like it’s not working. Give spaced repetition a few weeks and see how well you remember your content then; that’s the only way to really know how well it’s going. (This phenomenon is well-known and has a name, desirable difficulty.)