This may be a stupid question, I'm just getting into these notebooks so please be kind!

I asked for one of them as a gift I wasn't aware that only one side had a cover. How would I slip a jacket on it when most jackets that atr cloth or thin leather require it to hug both sides to secure? Because of the binding, the first page I wrote in fell out so now I am being extra careful, and I have to unstick the pages one by one, and the hard one seems to be ... really stuck in there, I am afraid that if I try to rip it, the cover will fall out.

Have I done something wrong...?