@ozgirl512 yup. And I've never heard it despite being kinda familiar with British sayings too. I find the nuances of the English language to be fascinating lol
I would say "thing", but it's not an expression I use or hear much. "Think" may be a mishearing, but it's one of those variations that actually makes more sense than the original 馃檪
People who say think have misheard the saying.. Or their parents misheard it and they have grown up thinking it is the actual saying.. Either way Thing is correct..