We cannot understand GAH!
it is one of those new-fangled teenager words, which is meant to communicate frustration.
Its origins stem from Tha Amanda, manda, manda, manda, manda, manda, manda, show!
It is an old show which ran on Nickelodean and is now in syndication world wide.
This being the case, and since it is now world wide, we cannot hope to stop GAH, only to contain it.
Incidently, Amanda Bynes is the Star of the orininating show, and the copywrite holder of the word GAH, please forward all objections to her.
Also, in current runnings of the show The Fairly Oddparents, the word GAH is used episodially
I reply by stating, DOH!