In Chapter 1072 Bonney encounters one of Kuma’s paw-shaped repulsions inside a room in Vegapunk’s laboratory, which she recognizes as her father’s memories. The repulsed memories were part of an experiment Vegapunk conducted on Kuma, after the former begged the latter to participate in it.
Vegapunk tries to prevent Bonney from accessing Kuma’s memories due to a promise he made to the former Warlord. According to Vegapunk, Kuma willingly gave up his own free will while participating in the Pacifista project.
I think the reason Kuma doesn’t want Bonnie to know his memories is because Bonnie is a clone of Kuma’s real daughter.
We’re going to get a flashback of Sorbet Kingdom. Kuma’s wife/mother was Connie and Bonney was his daughter. Either Kuma was a tyrant or was framed to be a tyrant, either way Sorbet got destroyed and both Connie and Bonney were killed.
Kuma changed his life afterwards and tried to become a better person, even joining the Freedom Fighters (not yet Revolutionaries) with Dragon and Ivankov. At some point he got Bonney’s body or DNA and made a deal with Vegapunk to become a sleeper cell/cyborg for the World Government in exchange for bringing her back to life as a clone. Kuma could even give her memories unlike the other MADS clones. The caveat is that Bonney can never know.
When Bonney touches his memories she’s going to see all of that, the fact the real her died and she’s a clone, and that her father wasn’t who she thought he was. It’s going to shatter her reality and sense of self. Everything Kuma has been doing has been to protect her from knowing she’s a clone.
*Theory by Schizochinia