I second everything haraya said about wool.
Someone who travels rough is going to get holes in cotton or poly items, too. The thing about wool is, when it's done right, it's very comfortable to wear. But it's not iron. It's not designed to be armor that can withstand anything. But neither is cotton. It's funny, we're perfectly fine to pay $200 for distressed denim with artfully positioned rips and holes, and washed, faded T-shirts, but we get our panties in a knot if we get a moth hole in a merino T-shirt.