Because I've been there, done that, then I know what is unnecessary, unneeded and totally frivolous.
That's pretty much the line of thinking I'm going on. I'll give you an example with hardware. When's the last time you had to sort out an IRQ conflict? Windows 2000? Maybe early on with Windows XP? It used to be important, but not anymore, thanks to OS improvements.
Now, with respect to the registry, there was a time when it was a good idea to understand it, because you'd be going there occasionally. Not so much anymore, especially not with Windows 7. My further proof is the permissions Windows 7 puts on system resources to keep you from easily messing with such things.
The OP would be much better suited learning other areas of the computer than an old technology that should have been removed from Windows OSes by now. With today's systems, there's little reason to ever consider entering the registry. I get what you are saying, FlliGi7, honestly. Five years ago or so, I would have agreed with you 100% or more.
If the OP really wants to learn something useful, that allows mods and customizations, configurations, etc....check out PowerShell.