Previously formed neural pathways, epigenetics, nascent research into gut microbiota and cognition. It's even more abstract and amazing than just software.

Erase the neuronic pattern and the frame work that led to a big part of what that person was still remains.

You lose memory, but there's a very real argument to be made that we're a trickier stack of firmware, software, and hardware acceleration to keep your analogy.

The newly minted infant homunculi in this hypothetical total loss of the "pattern" would (given their environment supports enough resources) find themselves becoming something significantly alike what was there before.

It happens all the time with smaller and not as thorough distractions to that pattern after all.

That's my take anyhow.