How do I know if I'm outgrowing 16GB of RAM?

Yes, there are clear signs. Watch memory usage in Task Manager or Activity Monitor — if it’s consistently over 80% during normal work (browser with 10 tabs, Slack, Spotify, office docs), you’re maxing out. The real giveaway is swap file usage, felt as stuttering, lag when switching apps, or a constantly running fan. If you reboot and the problem returns within an hour, or you run VMs, Docker, or large datasets, you need more RAM.