Hi Brian,

> When I try to boolean the holes in the helm I also get a
> set of holes at the back--seems very odd?

It looks like you figured it out already, but just in case - what seems to have happened here is you arrayed not only your cylinder, but the original circle curve that created the cylinder as well.

Then probably those circle curves got selected as cutting objects in addition to the cylinders.

When you use a curve as a cutting object in a boolean operation, it will slice all the way through the object, it won't only cut just the front side of it.

Nice flag at the top, you are really getting the hang of things!

- Michael