You’re sidestepping the transporter paradox, which I believe is substantially the same as that presented by Kurzweil’s projection.
But aside from that, and in context of my own life experience, it’s hard for me to say that “I” am some presence continuous with my youthful self, as it’s such a one way street, you know ... looking back. And a narrow street, too!
The transporter is fiction. Without knowing how it works, nothing can be said about it in reality.
But what's the difference between "you" and your youthful self? The state of your body? Memories? All those things are things "you" experienced. None of them were ever the "you" that experienced them. You're conflating your "self," your experience of "I," with your personality. But they aren't the same - "you" are aware of your personality. In fact, "you" are what is aware your personality has changed over time.