regex help

[Linux for blind general discussion]

Wait... so instead of typing something like:

mv longTitle:longSubtitle.pdf longTitle.pdf

when I want to truncate an overly long filename to something more
manageable, I could instead type

mv longTitle{:longSubtitle,}.pdf

instead?

If I'm understanding that right, than I'm having a "why is this the
first time in roughly 15 years of using Linux I've heard of this?!"
moment. Sure, tab completion works well and truncating just a bit from
the beginning of a filename or all but a bit at the end is easy
enough, but this sounds like it should make truncating the end of
afile name or the middle section much easier.

Also, some of those examples are starting to remind me of sed
commands... if I copy a bash script that's just the shebang line an a
bunch of sed commands and edit the copy to replace sed with rename, is
the resulting script likely to do to file names what the original
scrip does for the contents of text files? Or is my brain's pattern
matching throwing a false positive?