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When did "here's the thing" become everybody's favorite catchphrase?
Samuele “Outlaw Torn” Mattiuzzo's profile photoPete Hardie's profile photolorenz huelsbergen's profile photoJoe Willrich Lutalo's profile photo
See, here's the thing...
Exactly when "Look:" and "So.." ended..
I know you are interested in catchphrases, but here's the thing: I want to talk about what's important to me irregardless of what you've said, and am willing to use a catchphrase to make it sound as though I'm not just changing the subject.
So, the thing about "catchphrases" is that they become habits.  Look,  here is the thing, catchphrases are epic, win, turn-key that the evangelist and the SEO, let alone the guru, will use to crowd-source the meme...
Here's the thing, at the end of the day, we're going to double down on viral social marketing tweets reshare social social.
I've noticed a lot of "periods" lately. Especially, when someone makes some sort of political statement. That one is supposed to shut down any arguments, I guess. "Lowering taxes, increases revenue. Period". "Monkeys have wings. Period."
I propose replacing it with "Aye, there's the rub"
I'll trade all you your "here's the thing"s for just 1/10th of my "likes" I hear everyday.  You, like, know what I'm like saying?  
Here's the thing...I fucking hate "Here's the thing"
And yet I still have no idea where the thing is! >=(
Well, we used to say 'here\'s the thing', but the new way is much better
Well, not sure if that is where it came from, but Leonard from Big Bang Theory uses is a lot.
Probably right around the time The Thing became "the thing"
We live in Germany, but are a bilingual family. And a few days ago, my nine-year-old daughter used "Say what now?" for the first time in a conversation. We have no idea where she picked that one up -- best guess is listening in on some episode of How I Met Your Mother. 
"here's the thing" was from Scrubs. It was one of Dr Cox's catchphrases.
I don't know when it started, but it was in The West Wing, so it's not new.
Argument from authority is always around. 
''' Here's the thing .. ''' was previously popular as
''' So... ''''
'''' The ground truth ''''
''' Bottom line '''
''' Brass tacks ''' [old school]
etc etc.
we should bring back "And now, for something completely different". But here's the thing, long story short, this is the bottom line.
If you listen with a little more attention, you'll possibly realise most people don't actually speak English [I don't know how much this applies to other languages].  They merely tie together learned phrases.
+Curtis Maloney - In Gene Wolfe's "Torturer" series, he wrote about a (far future) culture that had controlled the populace by reducing all speech to stock phrases.  However, he showed that even that did not remove the power of creative thought.