Echoing points made earlier, it is absolutely crucial do understand what exactly you are agreeing to when signing an agreement. It is very easy to simply sign without reading through the agreement, since it may take some time and some mental work to understand the exact terms. However, if the case presents yourself where you are in a situation you did not expect to be in, you cannot simply say you did not know that would happen or a certain part of the agreement didn’t apply. Signing is your statement saying that you fully understand the terms of the agreement, and stating such previous things would essentially spell out that you signed without understanding. Should this happen, not much can really be done since on paper you certified your understanding.