To correct their spelling

[FoxtrotFoxtrotSierra]

I'm a mature student and am a member of a Facebook group set up by one of the chaps on my course. Practically every post on it is making me want to gouge my own eyes out due to the text-speak or misspelling of very simple words.

In the last two days I've seen:

"Does anyone no" instead of "Does anyone know"
"Few" instead of "Phew"
My name all in lower case twice
Full stops instead of spaces

It's driving me potty!

WIBU to rewrite their comments underneath correctly? We actually have lessons on how to write (full stops at the end of sentences, appropriate use of lower and upper case letters) and I'm beginning to understand why!

Do younger people just not write how we oldies do anymore?

For a few years now I've found that my fingers frequently type a different word than my brain is thinking, usually an equivalent that sounds the same, "lose" versus "loose", "no" versus "know", "your" versus "you're" are all examples.

These are all things where I am absolutely clear on what is correct, and I don't think i would have made these types earlier in my life. (Refuse to call them spelling mistakes as I do know better.)

I am worried that my brain is failing.

Actually I don't think I've done "lose"/"loose", but I have done "no"/"know", which makes no sense as they are so hugely different.