Insect metamorphosis is astounding. We know that a caterpillar is the larval stage of a butterfly or moth. When they form a chrysalis and change into an adult, all their cells are ripped apart into a mass of living goo, which then reorganizes into a butterfly. Now, neurobiologists who study humans cite evidence that our memories are coded by the connections between neurons in our brains. When these brain cells are separated as they in butterflies, one would think that the process destroys all the caterpillar's memories -but it doesn't! There might be something in the neurons themselves that retains memory, or in the chemicals that make up the brain, or there might be something in the process of metamorphosis that we don't yet understand. It could also be that insect brains are just way different from mammal brains.
What else is amazing is how they figured this much out. What kind of memories does a caterpillar have that we can study? Tom Lum of SciShow explains the research into insect brains and metamorphosis. There's a 45-second skippable ad at 3:30.