There’s a concept in psychology called the forgetting curve. It describes how, once you learn something, you gradually forget it if you don’t actively review. Learning to solve coding interview questions is no exception:
Even if I solve 200 algorithm questions on LeetCode and think that I understood solutions, after 2 months without solving any question, when I try to solve them again I can’t remember some of the solutions. What should I do to literally learn them? (answer)
I’m doing most of my writing on Quora this year. For more information, see A Project for 2020.