Interesting tell, 'not OK'. It's been in vogue--maybe 10 years now?--among people who've purged terms like 'evil' from their vocabulary.https://twitter.com/Google/status/894780243923292160 …
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
Later became mainstream adult language (presumably when those children grew up, whence bimodality). Ironic considering current use pattern.
Yeah, graph doesn't distinguish use-cases. "I'm not OK" has very different cultural context than "this is not OK".
can attest it was still in use this way in the 80s and 90s. usually understood as "not *bad* or *wrong*, exactly, but not ...ok, either"
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.