I'll point out that $a and $b cannot be stand-ins for "anything"

I chose my wording "should not be understood" carefully: it's a clarification for any reader for whom the distinction between $a || $b and @a || @b may be unclear. And maybe you missed the smiley at the end of my post above.

So you were jousting at stars [concern-trolling] that never felt a wound.

Says the anonymous poster making insults... he who lives in a glass house.