I have not done anything dippy! Ever! Never! Do I protest too much?
YES! I was smiling about this thread and checked my library account online. My dippy thing is I have a book being held for me and I already checked out another copy of it (before I requested the second from another branch library!)
I could think of others, but for now, I won't!

Editing to add....to late! I thought of a dozy of a dippy thing I did the other day.
I was extremely tired (like I will be later tonight because it is after 3am here!) and went to sleep by 9 PM. I got a phone call at 9:30 PM and I replied that the caller had the wrong number. They sounded surprised and so, I asked what number they had called. They repeated my number. I said, that is my number but you have the wrong number.
In the morning, I realized I could not remember what name they said, only it began with M. My name begins with M.
Oh dear! I called them back, left a strange message about how I could not remember the name they told me and if, they were calling for me, I was sorry. If it was a wrong number, just discard this!
I did not recognize the number, so I suppose it was double dippy to call them back. LoL