What does it mean that signal compounds and noise dilutes?

Each piece of signal you accumulate makes the next piece more valuable — noise does the opposite.

Example: Two engineers start the same job on the same day. One reads primary sources — RFCs, research papers, system design docs — and writes notes connecting each new concept to what they already know. The other skims Twitter threads, watches random tech talks, and bookmarks articles they never revisit. After three years, the first engineer sees architectural patterns instantly because every new system maps onto a dense web of prior understanding. The second has consumed more content but retained less — each disconnected piece decayed in isolation. Same industry, same hours spent. Radically different compounding curves.

Try this: Pick a domain you've been learning for at least six months. Draw two columns: Signal (concepts that connected to other things you knew and changed how you think or act) and Noise (content you consumed that you can't recall or that never connected to anything). Count the items in each column. Now estimate the hours spent on each category. The ratio between signal-hours and noise-hours is your current compounding rate.