The “eggshell skull” is a memorable torts doctrine from law school. Less memorable is the apportionment of damages for aggravation of a pre-existing condition. Both address how to award damages to an injury-prone person. The former provides that a tortfeasor takes a person as they are, including pre-existing conditions, and pays for all damages caused. The latter provides that a tortfeasor does not pay for damages it did not actually cause, even if the person is already injured because of a pre-existing condition. The distinction is fine, but, as the court of appeals found, the difference is a tortfeasor pays for everything if a plaintiff has an asymptomatic pre-existing condition, but partial damages if he/she has a symptomatic pre-existing condition. The court also determined that disability benefits are not a collateral source and not subtracted from total damages.