It somewhat makes sense if you think of it in terms of a really complicated 1.5GB metaprogram with a huge pile of conditionals that are triggered by the programs it itself writes (proteins). The final you is made up of an incomprehensible huge number of copies of the metaprogram, running different configurations, and spitting out programs to each other which then do more stuff. Our human brains can't really conceive of a configurable metaprogram that writes programs by interacting with itself in different configurations that it itself sets up.