Stapling

I think I am too stupid to staple things together. After about one and a half years I am now at my third stapler. At some point it just won't staple anymore. They don't go through...I have no idea what I am doing wrong but it must be something I am doing wrong....So, because I am too embarrassed to ask for a new one I snatched one from somebody else's desk since they left. I hope I don't break this one. It's heavier so now my wrist hurts. Can you tell I'm blond?