The phrase “Top of Mind” or variants, for something people are thinking quite a bit about, seems to be popping up. Who started it? I just saw it used on NBC News tonight, and somewhere else on TV over the last weekend.
I know “Top Of The Deck” or variants was used to refer to the most frequently used credit card in a wallet.
If I may offer a WAG, perhaps this is a metaphor based on the notion of a push-down (last in, first out) stack in computer programming (combined with the belief that the human mind works like a computer).
Google ngram viewer for top of my mind. It’s been around for a century with a real peak during WWII.
Top of mind is more recent, though I’m sure it formed from the other. It appears to be business jargon that developed in the 1960s and took off recently.
Top of mind is marketing/marketing research research jargon for the first thing people think of when they think of a category of goods or services. Companies strive to achieve top-of-mind awareness, and it is frequently correlated with sales, which is hardly surprising. I don’t have data for gross activity in the market-research industry, but I wouldn’t be surprised if it correlated well with Exapno’s ngram of the term.
Does the OP mean to include “top of my head” (as in, “I can’t think of an answer off the top of my head.”) as a variant of the same expression? Or is the OP asking about the phrase “top of mind” as distinct from “top of my head” ?
“Top of my head” is an old phrase that’s been around for a long time.