Even folks without significant cognitive impairment get baffled by really obscure comment text. If it does not literally say "leave a comment", "speak", or something directly related to commenting, it becomes a puzzle that I have to work out. The worst example I can think of is "down to acorn" for "reply to this comment". I have to look at the links to figure out which is which, every single time, unless I have been in there recently. It is difficult for me, and I am not impaired. I boggle to think of how difficult it would be for someone who is impaired.