I can’t google any reference to “if you thought that ... coming”.

You do right to shut the door, although a sharp kick would probably dislodge it.

Without wishing to go round the roundabout yet another time, may I humbly suggest that “You’re gonna get what’s coming!” derives from the “thing” usage which, ahem, derives from the “think” usage.

That’s why I came here in the first place.

Any guess what the Yes song was referring to? One could be a roundabout and enjoy it. Or one could just be taking a turn in a spiked barrel.

No offense. I’m just trying to provoke discussion, which may make me an agent provocatuer…

we all have to get used to the fact that both usages are correct.

The question is not (at least for me) which usage is “correct” (since whatever a lot of people say is correct in their dialect) but which came first.  It would take an overwhelming amount of evidence and semantic explanation to convince me that the “thing” usage came first; it seems to me clearly parasitic on “think.”

Absolutely. It was several hundred years ago that that French philosopher (Pascal? Descartes? Jacques Tati?) fell into the goldfish pond at the Petit Trianon and shouted out “I sink! Zerefore I exist!”, and was pulled out by a pragmatical Englishman, who said “You wotten fwog-eating Fwenchman, jutht for thaying that you have another think coming” and pushed him back in. It is on record that Pascal, Descartes et al. did, in fact, exist, or at least, thought they did. So do we. In time, we may have another think coming.

An earlier discussion of the nitpick-error law.