Why can't I save a document with a question mark, colon, exclamation point, quotation marks, in the title

In a more technical explanation, the operating system code that figures out paths and filenames in the file system uses those characters for special meanings. For the list in your original post:

• question mark - a "wildcard" character meaning "any single character"; similarly, the asterisk is a wildcard meaning "any string of characters"
• colon - separates the drive letter from the rest of the path
• exclamation point - used in batch files to surround environment variable names when delayed expansion is turned on (very geeky stuff)
• quotation marks - required to surround any path or filename that contains any spaces

The other characters listed in https://docs.microsoft.com/en-us/windows/desktop/FileIO/naming-a-file also have special meanings in paths and filenames.

The operating system code could try to guess when one of these characters represents the character itself rather than the special meaning, but that would make the code even more complicated than it already is, and would probably guess wrong quite often. Instead, the characters are just banned from filenames and paths.

IF you create your own Operating System as an alternative to Windows, then you may be able to do it.  However in the Microsoft Operating System such characters simply cannot be used in filenames because that is the way in which the system is designed.

Are you seriously giving me that as an answer? If so, you didn't  understand my question. "I have never understood what the deal is with saving a document title that has punctuation marks, particularly,  question mark, colon, exclamation point, quotation marks." Those characters are routinely denied in saving a document in Word. The dialogue box, using the attempted filename, says that the name is invalid. You don't get that? OK, your Word, and my Word, are different "Word's".

Thank you Diane. The article is over-the-top informative, but it still doesn't satisfy MY question. "Why can't I?". It seems to me that, there is really no "good" reason to deny characters in saving a file, or, renaming a file, because there are occasions when someone wants to use a character for a particular use. There are enough characters, or, make up their own, to leave simple characters to common people to use to save, or name their files.

Again, I thank you for your assistance. I'll probably get my head into that article in the future, because someone is gonna ask me that same question again, and I'll hopefully, have a semblance of an answer based on that. Thank you very much.