> Minors can't enter contracts, either, so your parents entered you on your behalf when you were born. You maintain it by staying here.
Or it is null and void when I turn 18.
> You're welcome to leave whenever you like.
And so are you. So there. It is pointless to counter criticism of society with "move to Somalia if you don't like it" and similar absurd platitudes. It doesn't address the question at hand, and it also doesn't address the fact that people who disagree with the (faux) social contract does not have any less of a right to live in the same country as you do.
Imagine that you go to a party, and to your horror you discover that a mass rape is in progress. You try to intervene and say that this is just not right, but are quickly told that if you don't like it you can go down the street to that other party where there are no raping going on.
Slaves can't enter contracts, by birth or otherwise.
Minors can't enter contracts, either, so your parents entered you on your behalf when you were born. You maintain it by staying here.
You had an 18 year head start to decide before most of the social contract even takes affect, while using services largely tax-free.
You're welcome to leave whenever you like.