Samuel Clemens, a.k.a. Mark Twain, used to describe himself as a "relentless noticer" of human behavior.
It’s a skill essential to good creativity; from the comedian’s observational humor, to the screenwriter’s keenly observed tics that make his characters come alive. Indeed, studies suggest that so-called 'creative types' walking into a room notice as many as twenty-five specific details, whereas 'non-creative types' may observe only ten.
Relentless noticing––and recording those observations––is the idea well into which one drops the bucket.