First, i want to start with Brook’s age. We all know that he is really old. In this panel of Brook’s background story we can see that Brook is already over 90 years old (38 years old + 50 years flashback + 2 years timeskip).
In Brooks introduction he said: “It has been a long time since i began drifting on this sea”.
So Brook has the potential to have a lot of information of the past.
Here are two examples:
-Brook heard of the “Rookie” Gol D. Roger
-Brook knows about the Vismokes from the past (maybe he has a secret connection with them too)
Currently we are now on Whole Cake Island and Brook is facing Big Mom. Brook will definitely play a big role in this arc! It’s the Soul Queen against the Soul King! In the previous chapter we saw a really epic panel of Brook and Big Mom.
In the last panel we can see Brook, which is calling Big Mom “Young Lady”.
How old is Big Mom? We can only speculate. It was never mentioned, but i guess about 70 years? (Whitebeard died with 72 and he is the same generation, like Kaido, Garp, Sengoku etc.)
When Brook is 90 years old it could be possible, that he met her in his past, when she was very young.
He is about 20 years older = 38 year old Brook meet 18 year old Big Mom (maybe she was hot… i doubt it) or at an earlier point, when she was still a little girl.
What do you think guys???
*Theory by Wolfram87