You and Rosinante were great friends, he was quiet, but you didn't mind.

You had a devil fruit, one to bring back anyone back to life, but with a cost. If you brought back someone to life, you would completely forget about the person you saved

You took that risk with Rosinante when you heard he died. Immediately, you grabbed your stuff and sought out to find him

One you did, you used your devil fruit. Passing out once you did. The last thing you saw was Rosinante, alive and looked new