First step is to get the hash from the docx file with office2john.py. It can be downloaded from github.
Second step to create a wordlist from the hints. Hint was: "He likes animals, he likes to speak like he's a hacker to make himself seem cool, and he was born in 1972."
Download an animal wordlist from github. "likes to speak like he's a hacker to make himself seem cool," could mean leetspeak.
I used hashcat to change the animal wordlist to leeatspeak and append 1972 to the end of all word.

hashcat --stdout Animal.txt -r /usr/share/hashcat/rules/leetspeak.rule -r 1972.rule > Animal_leet.txt
1972.rule was only: "c $1$9$7$2".

And finally password cracking with john:
sudo john --wordlist=./animal_leet.txt hash.txt

After opening the docx with the password, there was the result:
MetaCTF{not_all_meetings_are_secret}