This sort of thing ought to be taught in high school, along with other basic adult concepts like how to get a bank account, how credit cards work, how to vote, and how to pay taxes.
It's bizarre how such important things are left to each person to learn on their own on an ad hoc basis.
The fact that a contract is very much a legally binding document that you can't easily walk away from is not given nearly enough emphasis in the UK school system.
When I got hired by Microsoft, I was specifically told to get a lawyer to review the contract before I sign it. I did and my lawyer promptly told me the same at the person here, which is that the two non-compete clauses were so broad as to be unenforceable.
When a "partner company" to my MSFT division kept hiring our staff, Microsoft didn't try to enforce the non-competes, but instead threatened to sue the partner if they kept at it.
It would, if we weren't living in a world where courts had consistently held that things like this changing the employment contract after it begins are just as valid, because continued employment is sufficient consideration for them to be valid (the exception would be if the original employment contract had, e.g., a set term, but that's unusual.)