It is worth remembering that law professors have a vested interest in making sure the system work as you described. If contract law was straightforward, they'd be out of job.
However, it's worth noting the universe is a cesspool of corruption. If you pretend it works the way it ought to and not the way it does, you won't have a very good time or be very successful. The entire legal system is f-ed, and if you pretend it's anything else, you'll end up in prison or worse.