Every DSA platform I'd used explained the answer, then quizzed me on it. I could always follow the explanation. I could rarely reconstruct it a week later.
The pattern I kept noticing in myself: when someone made me sit with a question I couldn't immediately answer — actually sit with it, not skip ahead — the eventual answer stuck in a way explained answers never did. That observation is the reason Velocity's tutoring engine is built as a Socratic state machine instead of a content-delivery system. It's not a pedagogical trend I adopted; it's a question I couldn't stop noticing in my own learning.