Every single time I type a path or filename (or server name) in the shell, or in Windows explorer, or in a file -> open or save dialog, I don't trip over capitalization. If I want to glob files with an 'ecks' in the name I can write *x* and not have to do it twice for *x* and *X*.

When I look at a directory listing and it has "XF86Config", I read it in my head as "ecks eff eight six config" not "caps X caps F num eight num six initial cap Config" and I can type what I read and don't have to double-check if it's config or Config.

Tab completion works if I type x<tab> instead of blanking on me and making me double check and type X<tab>.

Case sensitivity is like walking down a corridor and someone hitting you to a stop every few steps and saying "you're walking Left Right Left Right but you should be walking Right Left Right Left".

Case insensitivity is like walking down a corridor.

In PowerShell, some cmdlets are named like Add-VpnConnection where the initialism drops to lowercase after the first letter, others like Get-VMCheckpoint where the initialism stays capitalised, others mixed like Add-NetIPHttpsCertBinding where IP is caps but HTTPS isn't - any capitalisation works for running them or searching them with get-command or tab-completing them. I don't have to care. I don't have to memorise it, type it, pay attention to it, trip over it, I don't have to care!.

"A programming language is low level when its programs require attention to the irrelevant." - Alan Perlis.

DNS names - ping GOOGLE.COM works, HTTPS://NEWS.YCOMBINATOR.COM works in a browser, MAC addresses are rendered with caps or lowercase hex on different devices, so are IPv6 addresses in hex format, email addresses - firstname.lastname or Firstname.Lastname is likely to work. File and directory access behaving the same means it's less bother. In Vim I :set ignorecase.

In PowerShell even string equality check is case insensitive by default, string match and split too. When I'm doing something like searching a log I want to see the english word 'error' if it's 'error' or 'ERROR' or 'Error' and I don't know what it is.

If I say the name of a document to a person I don't spell out the capitalisation. I don't want to have to do that to the computer, especially because there is almost no reason to have "Internal site 2 Network Diagram" and "INTERNAL site 2 network diagram" and "internal site 2 NETWORK DIAGRAM" in the same folder (and if there were, I couldn't easily keep them apart in my head).

All the time in command prompt shell, I press shift less often, type less, change directories and work with files more smoothly with less tripping over hurdles and being forced to stop and doublecheck what I'm tripping over when I read "word" and typed "word" and it didn't work.

On the other hand, the edge cases it causes me are ... well, I can't think of any because I don't want to put many files differing only by case in one directory. Maybe uncompressing an archive which has two files which clash? I can't remember that happening. Maybe moving a script to a case sensitive system? I don't do that often. In PowerShell, method calls are case insensitive. C# has "string".StartsWith() and JavaScript has .startsWith() and PowerShell will take .startswith() or .StartsWith or .Startswith or anything else. That occasionally clashes if there's a class with the same name in different case but that's rare, even.

In short, the computer pays attention to trivia so I don't have to. That's the right way round. It's about the best/simplest implementation of Do What I Mean (DWIM) that's almost always correct and almost never wrong.