Random googling indicates brains have about 10^9 synapses per cubic mm. Say one byte = ten synapses then that&#x27;s 100mb &#x2F; mm3. Say one hiding place gets encoded in 100 bytes. That&#x27;s potentially 1 million hiding places &#x2F; mm3. So it probably doesn&#x27;t need super compression.<p>It&#x27;d be interesting to figure how the thing works though.<p>I hazarding a guess at some sort of image recognition. If you went to a hiding point, took a snap with your phone and returned next year you could probably locate the spot by moving until the relative positions of trees etc in the image were the same. Something like that perhaps?