Omg, it's an inside-joke at our company now.

Anytime something happens on a server that's been running great for years, like a hard drive going bad or the time one literally caught on fire...

98% of the time it is selinux that is the reason it is doing weird things after the main fix because selinux changed a setting on the reboot.

"Have you checked selinux?" is the go to question whenever anything breaks now, even if it's not a computer.

We tend to forget about it these days, but the Unix permissions model was criticized for decades for being overly simplistic. One user having absolute authority, with limited ways to delegate specific authority to other users, is not a good model for multi-user operating systems. At least not in environments with more than a few users.

A well-configured sudo or SELinux can overcome this, which is one reason we don't bring it up much anymore. We also changed the whole model, where most people have individual PCs, and developers are often in their own little VM environment on a larger server.