Some waiting happens when one doesn't present in a clear cut way (which we have loads of experience with but we know lots of temporary shunt issues also pass) but there are things they can do and waiting too long is unacceptable - and the patient is not really in a position to advocate for themselves so you are stuck with being on top of things and learning when to push. No waiting should be due to not being born with it and if some surgeon gives you that then you need to light some fires under them or get some doctors who know better. Lots of surgeons treating adults are less familiar with hydrocephalus but the kids with this issue have been growing up for decades so being ignorant is not a solution.