From early childhood, I would hear this expression mostly on TV shows and movies, and I understood this as:
I always thought it was another “thing” coming. I don’t remember wen I became aware of it; it’s just one of those expressions that are so basic to the language one doesn’t remember that.
But I do vaguely remember the first time I heard
When I say “vaguely” I mean that I don’t remember the context or who spoke the words. I don’t remember how old I was, though I was still a kid. What I do remember was that I thought, "Shouldn’t that be “thing”.
While I most likely couldn’t have explained my thought processes at the time, I think I can fairly say that a few possibilities occurred to me:
[li]The speaker was saying “think” for humorous effect.[/li][li]The speaker was using some dialect in which “think” and “thing” have merged.[/li][li]The speaker mistakenly believed it to be “think”, the way people do mishear things, like mishearing “dog-eat-dog” as “doggy-dog”.[/li][li]It actually is supposed to be “think”, and I had misheard it in the first place[/li][/ul]
The problem with the dialect theory is that “think” and “thing” don’t exactly rhyme, at least not to me. “Thing” doesn’t rhyme with “sing” because the vowel falls somewhere between the /ei/ of “sang” and the /i:/ of “sing”.
The problem with the word in the second clause really being “think” is, where else do we see “think” used as a noun? When do we think thinks? ? On the other hand, I can think of at least one other example of a verbal root occurring in a stock phrase where it functions as a vowel: “without fail”, in which the word fail means “exception”.
So what do you think? Do I have another thing coming, or another think?