The big bad wolf's gonna get my Nanna!?

I had a dream when i was a child that there were open topped bathroom stalls outside my bedroom window and my Nanna (grandmother) was in one of them sitting down (i could only see her hair from above tho, yay dream censorship) and the big bad wolf was outside with cartoon dungarees and a red shirt on, pacing back and forward. Then i'd wake up after what felt like 15 seconds into it. I wasn't particularly scared, and he never found her, and i was too old for the big bad wolf anyway. I had this a few times when i was young, why do you think that is? And why can i remember this one and not any ones from recently?