Earlier quoted context omitted.
The article says that one possible reason the vaccine protects against dementia is incidental protection from other diseases. Getting chickenpox as a kid might protect you against shingles, but maybe not against those other diseases.
No! The opposite thing is true. Getting chickenpox as a kid drastically increases your likelihood of getting shingles as an adult. The initial chickenpox infection is the mechanism by which you're set up for shingles: you get it, fight it back, and it remains dormant in your nerves. Shingles is not simply chickenpox; it's the secondary infection you get from a resurgent zoster outbreak based in your nerves. Don't get…
Sadly it came back positive for antibodies. I was really hoping I had somehow evaded it, and could get the vaccine as an adult.