I think it's because you have grown more as an inevitable part of going through these life experiences - you probably could or would have become this person or someone equally admirable, over time, had he lived, but he does live as a part of you, always. Even as you have evolved to become a different person with Mr P. They're both a part of your story and eternal parts of your consciousness.

The new self you are now, is partly because of B, and so it's the biggest honour to his life that you are thriving and carrying forth your new self with all you learned, from loving and losing him. <3