ELI5: why is it that siblings grow up to be totally different despite being in living and being in the same enviroment and place? is it genetics? do genetics and dna and all play the main role of all of our differences in what we like and dislike from a young age? how so?

ELI5: why is it that siblings grow up to be totally different despite being in living and being in the same enviroment and place? is it genetics? do genetics and dna and all play the main role of all of our differences in what we like and dislike from a young age? how so?