Certain tree-squirrels brains g r o w in size ~ time of nut collecting; postulate: they need [well, the extra er, 'memory neurons??] to find these later. They can remember exact location of 90% ..of up to 10, 000 locales (try that on your Garmin).

And after winter: the brain returns to the stock-room, that extra-RAM, shrinks.. 'til next time.

That is all
..now a bit of genetic eng'rg beforr Finals? for homo-sap.. Why not? ... but Keep the Memory we be so dumb so often.