mad_jock, that's... weird...
You know, you can ask your doctor for a bit more information. Ask for an antibody titre test. It's just a bit of blood you have to give. It should show a normal titre for someone who's been previously exposed to chickenpox. If it's low, you're probably right in that you're still susceptible. You can discuss trying the vaccine anyway with your GP. You have no other immune issues, right?
BTW, anyone with chickenpox or shingles is infectious and can give it to children who haven't had it yet. mad_jock, you can consider it payback if you wish.
