Garp is such a tragic character
Garp literally failed in so many cases ,but actually always tried to do his best to put his loved one on the for him right path.
Raising his son ->became an revo
Raising his grandson wanting him to become a marine ->Grandson wants to be PK
His former Student Kuzan ,who he spent more time with than Dragon ,Luffy and Ace together->joined Pirates and left the navy
Gave a promise to Roger to protect his son because of his morals ->Ace died at Marineford can‘t imagine the grieve this man went through at MF.
The line of Kuzan that Garp has a habit in raising enemies hit hard ,because Garp is fully aware of that himself i think.