In Coimbra Portugal, high on the top of a hill, there sits an ancient and storied university. Within it there's a library - but not just any library. The Biblioteca Joanina as it's known, may be a single room, but it feels like a palace. Climbing five levels up, every inch of every wall is covered with books, some dating five centuries back. At 250,000 volumes it's stunning and impressive, so it's no surprise that it was the library chosen to bring Hogwarts and Harry Potter to life. Yet for all its wonders, the most captivating thing it contains is the easiest to overlook: a handful of scraps of white paper sticking out here and there from amongst its volumes. Their meaning and use are fascinating, but it's the oft overlooked sources of value, perspective, and forward progress they remind us of that offer so much more than meets the eye.

"Ghost books," the curator tells me they're called. "When someone removes a volume from the shelves," he continues, "a slip of paper is inserted where the book rested. It tells anyone who comes across it what volume was there and who has it." While at first the markers appear as simple cogs in an archaic, unsophisticated check out system, their simplicity belies their greater power. Ghost books are really the nodes and the anchors of a powerful human web, reminding the university's scholars about far more than just where a book belongs. Indeed, it's the ghost books' other functions we'd all be wise to borrow as metaphors and guides in our own busy efforts to learn, to advance, and sometimes just regain forward momentum. Here are a few worth checking out ...

Calling out the value that's already there.

A quarter of a million is a lot of books, so many that the value of any one can be easily lost among its many brothers and sisters. Trickier still, new books and new knowledge are added all the time. Our own work desks, even our brains, can feel the same - so much data from so many channels, that it's hard to keep it all straight. Still, our reflex is to keep looking outward and adding. We default to the idea that any new insight for breaking through is yet to be and will arise from elsewhere. We forget value that already exists.

In Coimbra, ghost books placehold but they also function as reminders of already accumulated value. "Someone is using this," the white slip signals, while also quietly declaring, "someone knows or senses the value within what's already here and right in front of us." A ghost book is like a jog to the brain to consider if the insight we seek might already be within our databanks. In the search for new, it's easy to overlook what we already have. We do it individually. It happens collectively. We're even culturally absentminded. Sometimes it's good to leave ourselves a little reminder to pause and look right in front of us for what we seek.

Reminding us we're not alone (nor all-important).

Our mountainous individual to-do lists don't just run the risk of burying value that already exists, they can block our ability to see that our colleagues are chipping away at their own parallel versions. The ghost book calls this forth too. Imagine strolling the shelves at Coimbra (if you could be so lucky) and seeing a ghost book with Maria Santos' name on it. "Huh," you might think to yourself. "I wonder why this book has value to Maria. What is she up to in her work?" Imagine further that she's checked out the same book you were looking for. Take note, it's the implied reawakening, not the dialog here, that's important.

At one level, the pause of the ghost book causes us to wonder - about someone other than ourselves, about their work and what they're up to, maybe even how what they're up to connects with what we're up to. But whatever the specifics, we remember to wonder. When we do, somewhere within we also recall that inevitably we need others for that spark of wonder to catch flame. More than just a powerful way to gain new ideas, wonder helps us gain perspective.

But there's another level of reminder here as well, that is if we can clear the clutter in our heads long enough to see it. The ghost book acts as a trigger of recognition that our version of importance and priority isn't the only one.

Giving us anchor in the waves of distraction.

No matter who you are, you're living through a time of great upheaval and interference. While the impacts of this volatile and unpredictable new century are many, one universal result is this: It is so darn easy to get distracted. Again, the ghost book offers help. In the Coimbra library system, this simple tool says, "Hey you there! That book you took out and then proceeded to become absorbed in? It belongs right here, part of the larger order it's connected to. Don't forget to come back and connect, no matter where its insights take you." Beyond the walls of the Biblioteca Joanina, the ghost book is a reminder to each of us to give ourselves an anchor, someplace to come back to - if not to reestablish order, to at least remind ourselves to check in with the larger context and the reasons why we are so busy doing what we do. Such anchors need not be fancy, they just need to exist and be used.

This deep into this quiet library moment, it's worth asking yourself - What's your ghost book? What's that little habit or device you use to recenter? If you don't have one, where do they exist around you that you could borrow the idea? If you do have your own version, how might you spread it to others? Could you have a collective version you could help each other use? Increasingly we all need aid in sorting the maelstrom we're collectively living in these days. Admitting that can feel overwhelming. What the ghost book reminds us is that bringing some order to it all can be simple, quick, even reassuring that there is a path, both forward and back, and sometimes all we need is a way to call it out.