Usually when the ventricles are enlarged and the patient has headaches, it usually means that they're shunt is blocked.
Hydrocephaly is caused by a failure of normal neural fold development, that usually occurs around the third to fourth week of development of the embryo. It is also around this time that the embryo begins to develop the lung buds, that will eventually become the lungs. If a baby is born, with either of the two defects you've mentioned, there would have been nothing a neonatologist or physician could have done to prevent the development of that defect as it is a failure of development, often caused by a genetic abnormality, not something that could be prevented. If the person who has one lung only discovers it at 23 years of age, it would seem that they have been functioning at an acceptable level and not been impacted by respiratory deficits. While having one lung is not optimal, a person can live a normal life with just one.
Some tips in the links below.
Rev. Billy Graham has normal pressure hydrocephalus (NPH).
Hydrocephalus is a condition in which there is excessive cerebrospinal fluid (CSF) in the brain. There are two types obstructive and communicating. Any tumor can cause this problem. Inflammatory narrowing and vascular malformations are other causes.
In communicating variety there is no block to the flow of CSF. The condition is due to impaired absorption of the CSF or rarely due to excessive production of CSF.