> How can I disable the Elisp syntax helper that appears in the
> echo area?
> 
> I don't even know what triggers it?
> 
> And after it pops up, the text remains even after
> I move point.
> 
> Annoying!
> 
> But I see its value ... if it can just be disabled I'm happy.

`eldoc-mode'

Yeah, it's annoying.
It used to be opt-in, now it's opt-out.