This is the 8300th most frequent Polish word.
pamiętnika
"Pamiętnika" means "diary" or "journal" in English.
In this sentence, 'pamiętnika' is in the form used for addressing the object (diary) in casual speech, asking whether the person possesses it or referring to their personal diary.
Czy masz swojego pamiętnika?
Do you have your diary?
Here, 'pamiętnika' is used to denote the instrument of writing, signifying the book where the person wrote thoughts and emotions.
Wczoraj pisałam w pamiętnika o moich uczuciach.
Yesterday, I wrote in my diary about my feelings.
In this usage, 'pamiętnika' refers to the content inside the diary, implying the excerpt or passage being searched for.