Even weirder conceptually than that: you have the same dna in all your cells. So why is your brain your brain, your eyes your eyes, and so on? Then you learn that not all genes are expressed all the time. Then you learn even among those expressed genes that they could have been spliced differently and resulted in completely different protein structures. No magnets needed for this example of phenotypes extending beyond mere dna sequence, just a mirror to look at yourself.