Nothing here is exotic. The first week has a vocabulary nobody gives you, the mask leaks in ways that are easy to misread, the numbers arrive without translation, and your own data turns out to live somewhere you did not expect. Each of those is one click away below.

The people who stay on CPAP are, almost without exception, the people who can see what is happening — hours, leaks, the figure — and fix the one thing that is off before it becomes a reason to stop.