When you live on Mars and not Palo Alto, you need to bring a lot of food. You don’t want to resort to eating your cars like the man from Mars in that Blondie song.
If we discover life on Mars, one fear is that we will not be able to defend ourselves from Mars pathogens.
We get around 500KG of unsterilized martian rocks landing on earth every year. I guess we already have the martian flu.