Yes, those of you born before 1980 will recognize that as an actual library card catalog. This one was originally in a library at the Harvard Business School.
I've wanted one of these since I was a child. Some people will get this idea immediately, others won't, and those born later than 1980 are still wondering what this thing is and why it needs 72 drawers...
If you're in the group that gets it, well, I need say nothing more. But, if you find yourself in one of the other two groups, I'll try to explain.
First, you have to remember that there was a time when there was no Wikipedia, there was no Google, personal computers were not everywhere, and, in fact, there was no Internet.
OK, sorry, I should have warned you, or at least built up to that more slowly.
Anyway, back then if you wanted to know something, you couldn't just look it up. You had to go to the Library, and then you could look it up. Libraries were the Storehouses of All Knowledge, and (it feels to me anyways) contained even more books than they do today.
Of course, since there weren't PCs or workstations everywhere, you couldn't just walk up to a screen and type what you were looking for and have it tell give you a recommended list of books along with reviews and feedback and "X number of people found this book useful in answering questions similar to yours".
Well, how did you you find the knowledge you were seeking then?
The card catalog.
If the library was the storehouse, the treasure trove of all knowledge, well, then the card catalog wasn't just a map -- it was the keys to the kingdom.
Within those drawers were hand-typed 3x5 cards that listed the books according to the Dewey Decimal System. You could look up these cards by title, by author, or by subject matter.
The Dewey Decimal number on the card you found would lead you to the correct section of the building, like a clue on a treasure hunt. It'd lead you to the right aisle, or if you were really lucky even to the correct bookcase. You'd still have to scan the shelves to find the exact book yourself -- and even then it wasn't certain that that particular tome would contain the exact knowledge you were seeking, which would mean another trip back to the card catalog -- but that was part of the fun.
Maybe you know someone who can always find things on Google. They've perfected the art of not only narrowing down the search criteria, but also of finding other ways to phrase it so that the search returns effective results. Working a card catalog well was like that, only it was hands-on.
If you were experienced, you'd look things up 3 or more ways up-front, scribbling your titles and Dewey Decimal numbers on slips of paper the library provided so that you had you first best guess and 2 or more contingencies ready, saving yourself the return trip to the catalog, as it was likely to be centrally located, but the shelves you would be searching might not be.
Combination Treasure Map and Keys to the Kingdom of the House of All Knowledge. Who wouldn't love one of these things?