My dude, that happened in 2016…

Why?

The Umbrella Academy: in the first couple of series like nothing happens and everyone is very sad.

You have the bootloader, the initramfs, the boot procedure, systemd, PID 1, you can check the logs, you have all those little things that make the system work

Windows has pretty much the same concepts. These two books talk about all that in deep:

https://www.microsoftpressstore.com/store/windows-internals-part-1-system-architecture-processes-9780735684188

https://www.microsoftpressstore.com/store/windows-internals-part-2-9780135462409

Also check out this one: https://leanpub.com/perfbook