You're not the person you used to be. The fantastic, flamboyant, ruling-race vampire you used to be. You try not to think about the person you were before that.
Helen remembers. Druitt probably would, if his brain weren't fried by being, oh, Jack the Ripper and having an electrical abnormal in his head.
You still won't forgive him for that. It's one thing to kill people, it's another to be messy about it and lie to your friends about it, to let them blame you for what you've done and then find out it wasn't even really your fault.
Thing is, you can't take it back, because he'd remember anyway, and he'd hold your take-back against you for the next dozen decades. Possibly centuries.
You're still not sure if you'll even live centuries, now that you're not a vampire anymore. You won't ask Helen that, even though you know she wants to know nearly as much as you do. Asking her would mean something, and there are already plenty of debts to Helen that you can't repay or admit to.
That's just the way it is, isn't it? The famous Nikola Tesla never forgets and never forgives, except when you do.
But that Nikola Tesla died an age ago. You lost yourself first in a tiny room at Oxford University with source blood burning through your system, then lost the vampire you loved to be (and thought you would always be) in another little room in a kid's apartment in the USA.
You can try to bring him back, but after a spell of being human for a while, you're not sure even he will be the same.
You can't stop trying, though. After all, what can the Five do with only three people left—only one who can kill people without giving a damn?
That you didn't drink human blood for ages didn't mean you didn't want it, or that you still don't want to revive the race.
Just that sometimes, you're not sure it would be the best idea.
And that's one thing that you will never admit to Helen.