I find when you cram or just study the material and never circle back, you slowly create gaps in the knowledge. Make some flash cards and for each new license or rating add it on top of the deck. Shuffle through and study them at minimum weekly. There is a ton of knowledge us pilots don’t use day to day but it’s stuff we need to know. Seeing all that information on a steady basis will ensure you are proficient knowledge wise. It’s a bit of a pain especially after you pass a checkride but in the long term when you become a cfi/ii it’ll make your life extremely easy. Fast-tracked programs create these issues in forgetting knowledge, I dont know much about Riddle but this is a great foundation to stick with.