What you learn this year makes next year’s learning cheaper. Knowledge stacks like interest.

Learning is not a series of separate downloads. Each thing you understand becomes a hook the next thing can attach to, which is why the tenth book in a field takes a fraction of the effort of the first. Early progress feels disproportionately slow for exactly this reason: you are building the hooks rather than using them.

Stay in one area long enough to get past the expensive part. When something new appears, ask what it resembles among the things you already hold. That connection is what makes it cheap to keep.