you've got another think/thing coming...

[CiderMonkey]

Which is the correct word for this phrase - think or thing? I have heard both used.

[Narolines]

Definitely think......as in "If you think that....(whatever)...then you've got another think coming."

[Quizmonster]

The idea behind it is that you've had one 'think' and come up with a notion which is grotesquely wrong - according to the speaker anyway! - so now you'd better have another 'think' coming, in the hope that you'll get it right this time. Anyone you've heard say 'thing' in these circumstances, Cider, had definitely got the wrong end of the stick, I'm afraid.