Why is "Mistake in English contract law" trending?

Wikipedia Overview

The law of mistake comprises a group of separate rules in English contract law. If the law deems a mistake to be sufficiently grave, then a contract entered into on the grounds of the mistake may be void. A mistake is an incorrect understanding by one or more parties to a contract. There are essentially three types of mistakes in contract:Unilateral mistake is where only one party to a contract is mistaken as to the terms or subject-matter. The courts will uphold such a contract unless it was determined that the non-mistaken party was aware of the mistake and tried to take advantage of the mistake. It is also possible for a contract to be void if there was a mistake in the identity of the contracting party. An example is in Lewis v Averay where Lord Denning MR held that the contract can only be avoided if the plaintiff can show that, at the time of agreement, the plaintiff believed the other party's identity was of vital importance. A mere mistaken belief as to the credibility of the other party is not sufficient.
Mutual mistake is when both parties of a contract are mistaken as to the terms. Each believes they are contracting to something different. The court usually tries to uphold such a mistake if a reasonable interpretation of the terms can be found. However, a contract based on a mutual mistake in judgement does not cause the contract to be voidable by the party that is adversely affected. See Raffles v Wichelhaus.
Common mistake is where both parties hold the same mistaken belief of the facts. This is demonstrated in the case of Bell v Lever Brothers Ltd, which established that common mistake can only void a contract if the mistake of the subject-matter was sufficiently fundamental to render its identity different from what was contracted, making the performance of the contract impossible. This is similar to frustration, except that the event precedes, rather than follows the time of agreement.