Along with mixed salad greens, the Post-it Note ranks as one of my top inventions of the late 1900s.

The Post-it was introduced in the U.S. in 1980, but the process of inventing it actually started in the late ’60s. If you ask me, it was a pretty backwards ordeal. It seems a 3M scientist had invented the repositionable adhesive in 1967 but couldn’t figure out what to do with it; he shopped it around the lab and none of the other scientists could come up with any sort of marketable product. It wasn’t until 1974 that another 3M scientist thought to coat the lightly sticky substance onto paper—and this only as a solution to marking his place in the constantly turning pages of the church hymnal.

It took six more years of testing to get the Post-it out to a national audience, from which the small-but-mighty notes have rapidly asserted their dominance in the ever-expanding world of office supplies, marking places in books and manuscripts, leaving notes on desktops and refrigerators, serving as a kind of pixel for windowpane art projects, even facilitating a new kind of peaceful protest.

Almost all of my uses of the Post-it fall into one of three categories:

1. the “note to self,” pointing out an as-yet-un-thought-of connection between one thing and another;

2. the “note to other,” providing direction or asking for clarification without wrecking the page, or;

3. not as a note at all but as an exclamation point, pointing to some tidbit of information that’s interesting without saying anything about it.

In the latter case, I’m hoping the bright colors of the note and position on the page (always just above the critical element) will jog my memory, but lots of times I run across Post-its I’ve left for myself in books and can’t remember why I found a passage interesting in the first place. It makes you realize how much of logic resides only in our heads—and that what’s logical to one person won’t, on the surface, have any decipherable logic to another without the connecting thought spelled out in plain English. Post-it notes can help make these connections, but they’re only as good as the brain pushing them into service.

In some ways, the use of Post-its mirrors the process of their invention: good things becoming great when they’re stuck together.

Mixed salad greens make all the connections for you, the perfect combination of flavor and color and texture right out of the bag. Of course, you’ve got to add the dressing, and there’s always the questions of other vegetables, but these issues seem easy by comparison.

I wonder if mixed greens got thought up backwards, too—lettuce packers looking for a way to market the random leaves that landed on the floor throughout the day—and how many scientists it took to work out the salad that was already there.