Prologue

In 1881, a German named Hermann von Ebbinghaus sits down at his desk, and he’s about to start a three-year experiment—on himself. Hermann was a man of science. He was committed. 

He was “a philosopher” back then because psychology didn’t exist yet. You might say Herman was the first psychologist.

In front of him, he’s got a metronome ticking away, a notebook, and a stack of papers with 2,300 nonsense syllables. The man had come up with 2,300 combinations of letters that meant absolutely nothing to him. Imagine, just sitting there, “Hmm, I need a random, meaningless syllable. How about ‘zob’? Nope, that’s too close to ‘zombie.’ Next! ‘Tre.’ Too much like ‘tree.’” This went on for 2,300 times.

So, Hermann grabs the first card with syllables, places it on his desk, and gets that metronome swinging at 150 beats per minute. And then he begins reading these syllables out loud, in this steady, monotonous voice, keeping five beats of the metronome between each syllable. So, he’s there like: “GAF… (tick, tick, tick, tick, tick) … DOK… (tick, tick, tick, tick, tick) … PIZ.” No emotions, no hesitation, just syllables and ticking. Die Ordnung must sein. 

When he finishes reading the first list of syllables, he looks up from the paper, takes a deep breath, and tries to recite them from memory. And—needless to say—he can’t remember all of them. So, reads them again, until finally, these random syllables are just flowing out of his mouth like free-style avant-garde poetry. He’s got it. He’s got the first batch of syllables memorized.

Then he takes a 20-minute break.

He gets back to his desk. Realizes he only remembers about 60% of the syllables. He scribbles this down in his journal and calls it a day. 

End of day one of das Experiment.

The next morning at 10 a.m., he sits down, ready to see how well his brain held up overnight. And, he only remembers 30% of the syllables. Only 30%. 

He does this every day, for three years (well, he had a little break, of few months worth). Testing himself religiously after ten minutes, an hour, yesterday, the day before, a week, a month, six months, even a year or two.

Oh, and he goes through all the 23,000 meaningless syllables from the jar. By the time the used-up syllables jar is full, his notebook is full of measurements on how quickly his brain tossed out this information.

Finally, after three years, he gathers up all his notes and puts together what we now call the forgetting curve. And in 1885, he publishes his work titled Über das Gedächtnis or On Memory.