Is Monty my hero?

I have a white male cat 2 yrs old, he is terrified of everything even the rustle of a plastic bag. I put a large piece of cardborad over my door to prevent the wind coming throught the letterbox and vents. (We have had 90 mile ph winds)I have never needed to that before.
   
My boy Monty, when I came out of the cloakroom, his tail was fully bushed out and he jumped to the top of the cardboard and tore it down,
   
I was so impressed as normally he hides away. I wondered if he was trying to protect me by attacking the cardboard or if he was playing.
   
Any suggestions?

He was either scared or angry - that's what a bushed tail means.
   
The fact that he went forward & attacked it meant he was either more angry than scared, and "fight" kicked in more than "flight".
   
I can't imagine why he considered it a threat...
   
Suggestion: Get (or record) a CD of the sounds that scare him, then play them at a VERY low volume, barely above "can't hear", for a couple of weeks, gradually upping the volume a touch at a time. (Remember: he can hear better than you.) Put the CD on "replay" for a few hours at a time, both when you're home and away.
   
This may get him used to the sound and consider it just background eventually.