0.2 The learning flow

Three phases, and each one builds the vocabulary the next one assumes:

   PHASE 1 (OS concepts)     teaches you what a "process," "page fault," or
        |                    "file descriptor" actually IS
        v
   PHASE 2 (Linux)           teaches you the COMMANDS that ask the kernel
        |                    about those exact things (`ps`, `free`, `lsof`)
        v
   PHASE 3 (Containers)      shows you that a "container" is just Linux
        |                    primitives from Phase 1, used in a clever way
        |                    -- and Docker/Kubernetes commands are, again,
        |                    just asking the kernel (via a daemon) to do
        v                    things you already understand.
   PART 20 (Go on Linux)     has you write the programs that make those
                             primitives visible -- and build a container
                             runtime yourself (optional, needs basic Go).

Skipping Phase 1 and going straight to docker run is possible — plenty of engineers do exactly that — but "why did my container get OOM-killed" or "why is this pod stuck in CrashLoopBackOff" stops being mysterious only once you know what's underneath. That's the whole bet this guide makes: go down one level, and everything above it gets easier to debug, not harder to learn.

The loop for every chapter:

   READ the concept  ->  see the REAL-WORLD example  ->  TRY IT on your own
   box  ->  answer the CHECK YOURSELF questions  ->  move on

Don't skip "try it yourself." Reading about fork() is not the same as watching a process count double.